net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54 #include <linux/hashtable.h>
  55
  56 #include "../netns.h"
  57
  58 static const struct rpc_authops authgss_ops;
  59
  60 static const struct rpc_credops gss_credops;
  61 static const struct rpc_credops gss_nullops;
  62
  63 #define GSS_RETRY_EXPIRED 5
  64 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  65
  66 #define GSS_KEY_EXPIRE_TIMEO 240
  67 static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
  68
  69 #ifdef RPC_DEBUG
  70 # define RPCDBG_FACILITY        RPCDBG_AUTH
  71 #endif
  72
  73 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  74 /* length of a krb5 verifier (48), plus data added before arguments when
  75  * using integrity (two 4-byte integers): */
  76 #define GSS_VERF_SLACK          100
  77
  78 static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
  79 static DEFINE_SPINLOCK(gss_auth_hash_lock);
  80
  81 struct gss_pipe {
  82         struct rpc_pipe_dir_object pdo;
  83         struct rpc_pipe *pipe;
  84         struct rpc_clnt *clnt;
  85         const char *name;
  86         struct kref kref;
  87 };
  88
  89 struct gss_auth {
  90         struct kref kref;
  91         struct hlist_node hash;
  92         struct rpc_auth rpc_auth;
  93         struct gss_api_mech *mech;
  94         enum rpc_gss_svc service;
  95         struct rpc_clnt *client;
  96         struct net *net;
  97         /*
  98          * There are two upcall pipes; dentry[1], named "gssd", is used
  99          * for the new text-based upcall; dentry[0] is named after the
 100          * mechanism (for example, "krb5") and exists for
 101          * backwards-compatibility with older gssd's.
 102          */
 103         struct gss_pipe *gss_pipe[2];
 104         const char *target_name;
 105 };
 106
 107 /* pipe_version >= 0 if and only if someone has a pipe open. */
 108 static DEFINE_SPINLOCK(pipe_version_lock);
 109 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
 110 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
 111
 112 static void gss_free_ctx(struct gss_cl_ctx *);
 113 static const struct rpc_pipe_ops gss_upcall_ops_v0;
 114 static const struct rpc_pipe_ops gss_upcall_ops_v1;
 115
 116 static inline struct gss_cl_ctx *
 117 gss_get_ctx(struct gss_cl_ctx *ctx)
 118 {
 119         atomic_inc(&ctx->count);
 120         return ctx;
 121 }
 122
 123 static inline void
 124 gss_put_ctx(struct gss_cl_ctx *ctx)
 125 {
 126         if (atomic_dec_and_test(&ctx->count))
 127                 gss_free_ctx(ctx);
 128 }
 129
 130 /* gss_cred_set_ctx:
 131  * called by gss_upcall_callback and gss_create_upcall in order
 132  * to set the gss context. The actual exchange of an old context
 133  * and a new one is protected by the pipe->lock.
 134  */
 135 static void
 136 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 137 {
 138         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 139
 140         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 141                 return;
 142         gss_get_ctx(ctx);
 143         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 144         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 145         smp_mb__before_clear_bit();
 146         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 147 }
 148
 149 static const void *
 150 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 151 {
 152         const void *q = (const void *)((const char *)p + len);
 153         if (unlikely(q > end || q < p))
 154                 return ERR_PTR(-EFAULT);
 155         memcpy(res, p, len);
 156         return q;
 157 }
 158
 159 static inline const void *
 160 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 161 {
 162         const void *q;
 163         unsigned int len;
 164
 165         p = simple_get_bytes(p, end, &len, sizeof(len));
 166         if (IS_ERR(p))
 167                 return p;
 168         q = (const void *)((const char *)p + len);
 169         if (unlikely(q > end || q < p))
 170                 return ERR_PTR(-EFAULT);
 171         dest->data = kmemdup(p, len, GFP_NOFS);
 172         if (unlikely(dest->data == NULL))
 173                 return ERR_PTR(-ENOMEM);
 174         dest->len = len;
 175         return q;
 176 }
 177
 178 static struct gss_cl_ctx *
 179 gss_cred_get_ctx(struct rpc_cred *cred)
 180 {
 181         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 182         struct gss_cl_ctx *ctx = NULL;
 183
 184         rcu_read_lock();
 185         if (gss_cred->gc_ctx)
 186                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 187         rcu_read_unlock();
 188         return ctx;
 189 }
 190
 191 static struct gss_cl_ctx *
 192 gss_alloc_context(void)
 193 {
 194         struct gss_cl_ctx *ctx;
 195
 196         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 197         if (ctx != NULL) {
 198                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 199                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 200                 spin_lock_init(&ctx->gc_seq_lock);
 201                 atomic_set(&ctx->count,1);
 202         }
 203         return ctx;
 204 }
 205
 206 #define GSSD_MIN_TIMEOUT (60 * 60)
 207 static const void *
 208 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 209 {
 210         const void *q;
 211         unsigned int seclen;
 212         unsigned int timeout;
 213         unsigned long now = jiffies;
 214         u32 window_size;
 215         int ret;
 216
 217         /* First unsigned int gives the remaining lifetime in seconds of the
 218          * credential - e.g. the remaining TGT lifetime for Kerberos or
 219          * the -t value passed to GSSD.
 220          */
 221         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 222         if (IS_ERR(p))
 223                 goto err;
 224         if (timeout == 0)
 225                 timeout = GSSD_MIN_TIMEOUT;
 226         ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
 227         /* Sequence number window. Determines the maximum number of
 228          * simultaneous requests
 229          */
 230         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 231         if (IS_ERR(p))
 232                 goto err;
 233         ctx->gc_win = window_size;
 234         /* gssd signals an error by passing ctx->gc_win = 0: */
 235         if (ctx->gc_win == 0) {
 236                 /*
 237                  * in which case, p points to an error code. Anything other
 238                  * than -EKEYEXPIRED gets converted to -EACCES.
 239                  */
 240                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 241                 if (!IS_ERR(p))
 242                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 243                                                     ERR_PTR(-EACCES);
 244                 goto err;
 245         }
 246         /* copy the opaque wire context */
 247         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 248         if (IS_ERR(p))
 249                 goto err;
 250         /* import the opaque security context */
 251         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 252         if (IS_ERR(p))
 253                 goto err;
 254         q = (const void *)((const char *)p + seclen);
 255         if (unlikely(q > end || q < p)) {
 256                 p = ERR_PTR(-EFAULT);
 257                 goto err;
 258         }
 259         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
 260         if (ret < 0) {
 261                 p = ERR_PTR(ret);
 262                 goto err;
 263         }
 264         dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u\n",
 265                 __func__, ctx->gc_expiry, now, timeout);
 266         return q;
 267 err:
 268         dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
 269         return p;
 270 }
 271
 272 #define UPCALL_BUF_LEN 128
 273
 274 struct gss_upcall_msg {
 275         atomic_t count;
 276         kuid_t  uid;
 277         struct rpc_pipe_msg msg;
 278         struct list_head list;
 279         struct gss_auth *auth;
 280         struct rpc_pipe *pipe;
 281         struct rpc_wait_queue rpc_waitqueue;
 282         wait_queue_head_t waitqueue;
 283         struct gss_cl_ctx *ctx;
 284         char databuf[UPCALL_BUF_LEN];
 285 };
 286
 287 static int get_pipe_version(struct net *net)
 288 {
 289         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 290         int ret;
 291
 292         spin_lock(&pipe_version_lock);
 293         if (sn->pipe_version >= 0) {
 294                 atomic_inc(&sn->pipe_users);
 295                 ret = sn->pipe_version;
 296         } else
 297                 ret = -EAGAIN;
 298         spin_unlock(&pipe_version_lock);
 299         return ret;
 300 }
 301
 302 static void put_pipe_version(struct net *net)
 303 {
 304         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 305
 306         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
 307                 sn->pipe_version = -1;
 308                 spin_unlock(&pipe_version_lock);
 309         }
 310 }
 311
 312 static void
 313 gss_release_msg(struct gss_upcall_msg *gss_msg)
 314 {
 315         struct net *net = gss_msg->auth->net;
 316         if (!atomic_dec_and_test(&gss_msg->count))
 317                 return;
 318         put_pipe_version(net);
 319         BUG_ON(!list_empty(&gss_msg->list));
 320         if (gss_msg->ctx != NULL)
 321                 gss_put_ctx(gss_msg->ctx);
 322         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 323         kfree(gss_msg);
 324 }
 325
 326 static struct gss_upcall_msg *
 327 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid)
 328 {
 329         struct gss_upcall_msg *pos;
 330         list_for_each_entry(pos, &pipe->in_downcall, list) {
 331                 if (!uid_eq(pos->uid, uid))
 332                         continue;
 333                 atomic_inc(&pos->count);
 334                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 335                 return pos;
 336         }
 337         dprintk("RPC:       %s found nothing\n", __func__);
 338         return NULL;
 339 }
 340
 341 /* Try to add an upcall to the pipefs queue.
 342  * If an upcall owned by our uid already exists, then we return a reference
 343  * to that upcall instead of adding the new upcall.
 344  */
 345 static inline struct gss_upcall_msg *
 346 gss_add_msg(struct gss_upcall_msg *gss_msg)
 347 {
 348         struct rpc_pipe *pipe = gss_msg->pipe;
 349         struct gss_upcall_msg *old;
 350
 351         spin_lock(&pipe->lock);
 352         old = __gss_find_upcall(pipe, gss_msg->uid);
 353         if (old == NULL) {
 354                 atomic_inc(&gss_msg->count);
 355                 list_add(&gss_msg->list, &pipe->in_downcall);
 356         } else
 357                 gss_msg = old;
 358         spin_unlock(&pipe->lock);
 359         return gss_msg;
 360 }
 361
 362 static void
 363 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 364 {
 365         list_del_init(&gss_msg->list);
 366         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 367         wake_up_all(&gss_msg->waitqueue);
 368         atomic_dec(&gss_msg->count);
 369 }
 370
 371 static void
 372 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 373 {
 374         struct rpc_pipe *pipe = gss_msg->pipe;
 375
 376         if (list_empty(&gss_msg->list))
 377                 return;
 378         spin_lock(&pipe->lock);
 379         if (!list_empty(&gss_msg->list))
 380                 __gss_unhash_msg(gss_msg);
 381         spin_unlock(&pipe->lock);
 382 }
 383
 384 static void
 385 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 386 {
 387         switch (gss_msg->msg.errno) {
 388         case 0:
 389                 if (gss_msg->ctx == NULL)
 390                         break;
 391                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 392                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 393                 break;
 394         case -EKEYEXPIRED:
 395                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 396         }
 397         gss_cred->gc_upcall_timestamp = jiffies;
 398         gss_cred->gc_upcall = NULL;
 399         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 400 }
 401
 402 static void
 403 gss_upcall_callback(struct rpc_task *task)
 404 {
 405         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 406                         struct gss_cred, gc_base);
 407         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 408         struct rpc_pipe *pipe = gss_msg->pipe;
 409
 410         spin_lock(&pipe->lock);
 411         gss_handle_downcall_result(gss_cred, gss_msg);
 412         spin_unlock(&pipe->lock);
 413         task->tk_status = gss_msg->msg.errno;
 414         gss_release_msg(gss_msg);
 415 }
 416
 417 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 418 {
 419         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 420         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 421         gss_msg->msg.data = gss_msg->databuf;
 422         gss_msg->msg.len = sizeof(uid);
 423         BUG_ON(sizeof(uid) > UPCALL_BUF_LEN);
 424 }
 425
 426 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 427                                 const char *service_name,
 428                                 const char *target_name)
 429 {
 430         struct gss_api_mech *mech = gss_msg->auth->mech;
 431         char *p = gss_msg->databuf;
 432         int len = 0;
 433
 434         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
 435                                    mech->gm_name,
 436                                    from_kuid(&init_user_ns, gss_msg->uid));
 437         p += gss_msg->msg.len;
 438         if (target_name) {
 439                 len = sprintf(p, "target=%s ", target_name);
 440                 p += len;
 441                 gss_msg->msg.len += len;
 442         }
 443         if (service_name != NULL) {
 444                 len = sprintf(p, "service=%s ", service_name);
 445                 p += len;
 446                 gss_msg->msg.len += len;
 447         }
 448         if (mech->gm_upcall_enctypes) {
 449                 len = sprintf(p, "enctypes=%s ", mech->gm_upcall_enctypes);
 450                 p += len;
 451                 gss_msg->msg.len += len;
 452         }
 453         len = sprintf(p, "\n");
 454         gss_msg->msg.len += len;
 455
 456         gss_msg->msg.data = gss_msg->databuf;
 457         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
 458 }
 459
 460 static struct gss_upcall_msg *
 461 gss_alloc_msg(struct gss_auth *gss_auth,
 462                 kuid_t uid, const char *service_name)
 463 {
 464         struct gss_upcall_msg *gss_msg;
 465         int vers;
 466
 467         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 468         if (gss_msg == NULL)
 469                 return ERR_PTR(-ENOMEM);
 470         vers = get_pipe_version(gss_auth->net);
 471         if (vers < 0) {
 472                 kfree(gss_msg);
 473                 return ERR_PTR(vers);
 474         }
 475         gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 476         INIT_LIST_HEAD(&gss_msg->list);
 477         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 478         init_waitqueue_head(&gss_msg->waitqueue);
 479         atomic_set(&gss_msg->count, 1);
 480         gss_msg->uid = uid;
 481         gss_msg->auth = gss_auth;
 482         switch (vers) {
 483         case 0:
 484                 gss_encode_v0_msg(gss_msg);
 485         default:
 486                 gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 487         };
 488         return gss_msg;
 489 }
 490
 491 static struct gss_upcall_msg *
 492 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 493 {
 494         struct gss_cred *gss_cred = container_of(cred,
 495                         struct gss_cred, gc_base);
 496         struct gss_upcall_msg *gss_new, *gss_msg;
 497         kuid_t uid = cred->cr_uid;
 498
 499         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 500         if (IS_ERR(gss_new))
 501                 return gss_new;
 502         gss_msg = gss_add_msg(gss_new);
 503         if (gss_msg == gss_new) {
 504                 int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 505                 if (res) {
 506                         gss_unhash_msg(gss_new);
 507                         gss_msg = ERR_PTR(res);
 508                 }
 509         } else
 510                 gss_release_msg(gss_new);
 511         return gss_msg;
 512 }
 513
 514 static void warn_gssd(void)
 515 {
 516         static unsigned long ratelimit;
 517         unsigned long now = jiffies;
 518
 519         if (time_after(now, ratelimit)) {
 520                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 521                                 "Please check user daemon is running.\n");
 522                 ratelimit = now + 15*HZ;
 523         }
 524 }
 525
 526 static inline int
 527 gss_refresh_upcall(struct rpc_task *task)
 528 {
 529         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 530         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 531                         struct gss_auth, rpc_auth);
 532         struct gss_cred *gss_cred = container_of(cred,
 533                         struct gss_cred, gc_base);
 534         struct gss_upcall_msg *gss_msg;
 535         struct rpc_pipe *pipe;
 536         int err = 0;
 537
 538         dprintk("RPC: %5u %s for uid %u\n",
 539                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 540         gss_msg = gss_setup_upcall(gss_auth, cred);
 541         if (PTR_ERR(gss_msg) == -EAGAIN) {
 542                 /* XXX: warning on the first, under the assumption we
 543                  * shouldn't normally hit this case on a refresh. */
 544                 warn_gssd();
 545                 task->tk_timeout = 15*HZ;
 546                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 547                 return -EAGAIN;
 548         }
 549         if (IS_ERR(gss_msg)) {
 550                 err = PTR_ERR(gss_msg);
 551                 goto out;
 552         }
 553         pipe = gss_msg->pipe;
 554         spin_lock(&pipe->lock);
 555         if (gss_cred->gc_upcall != NULL)
 556                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 557         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 558                 task->tk_timeout = 0;
 559                 gss_cred->gc_upcall = gss_msg;
 560                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 561                 atomic_inc(&gss_msg->count);
 562                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 563         } else {
 564                 gss_handle_downcall_result(gss_cred, gss_msg);
 565                 err = gss_msg->msg.errno;
 566         }
 567         spin_unlock(&pipe->lock);
 568         gss_release_msg(gss_msg);
 569 out:
 570         dprintk("RPC: %5u %s for uid %u result %d\n",
 571                 task->tk_pid, __func__,
 572                 from_kuid(&init_user_ns, cred->cr_uid), err);
 573         return err;
 574 }
 575
 576 static inline int
 577 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 578 {
 579         struct net *net = gss_auth->net;
 580         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 581         struct rpc_pipe *pipe;
 582         struct rpc_cred *cred = &gss_cred->gc_base;
 583         struct gss_upcall_msg *gss_msg;
 584         unsigned long timeout;
 585         DEFINE_WAIT(wait);
 586         int err;
 587
 588         dprintk("RPC:       %s for uid %u\n",
 589                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 590 retry:
 591         err = 0;
 592         /* Default timeout is 15s unless we know that gssd is not running */
 593         timeout = 15 * HZ;
 594         if (!sn->gssd_running)
 595                 timeout = HZ >> 2;
 596         gss_msg = gss_setup_upcall(gss_auth, cred);
 597         if (PTR_ERR(gss_msg) == -EAGAIN) {
 598                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 599                                 sn->pipe_version >= 0, timeout);
 600                 if (sn->pipe_version < 0) {
 601                         if (err == 0)
 602                                 sn->gssd_running = 0;
 603                         warn_gssd();
 604                         err = -EACCES;
 605                 }
 606                 if (err < 0)
 607                         goto out;
 608                 goto retry;
 609         }
 610         if (IS_ERR(gss_msg)) {
 611                 err = PTR_ERR(gss_msg);
 612                 goto out;
 613         }
 614         pipe = gss_msg->pipe;
 615         for (;;) {
 616                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 617                 spin_lock(&pipe->lock);
 618                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 619                         break;
 620                 }
 621                 spin_unlock(&pipe->lock);
 622                 if (fatal_signal_pending(current)) {
 623                         err = -ERESTARTSYS;
 624                         goto out_intr;
 625                 }
 626                 schedule();
 627         }
 628         if (gss_msg->ctx)
 629                 gss_cred_set_ctx(cred, gss_msg->ctx);
 630         else
 631                 err = gss_msg->msg.errno;
 632         spin_unlock(&pipe->lock);
 633 out_intr:
 634         finish_wait(&gss_msg->waitqueue, &wait);
 635         gss_release_msg(gss_msg);
 636 out:
 637         dprintk("RPC:       %s for uid %u result %d\n",
 638                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 639         return err;
 640 }
 641
 642 #define MSG_BUF_MAXSIZE 1024
 643
 644 static ssize_t
 645 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 646 {
 647         const void *p, *end;
 648         void *buf;
 649         struct gss_upcall_msg *gss_msg;
 650         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 651         struct gss_cl_ctx *ctx;
 652         uid_t id;
 653         kuid_t uid;
 654         ssize_t err = -EFBIG;
 655
 656         if (mlen > MSG_BUF_MAXSIZE)
 657                 goto out;
 658         err = -ENOMEM;
 659         buf = kmalloc(mlen, GFP_NOFS);
 660         if (!buf)
 661                 goto out;
 662
 663         err = -EFAULT;
 664         if (copy_from_user(buf, src, mlen))
 665                 goto err;
 666
 667         end = (const void *)((char *)buf + mlen);
 668         p = simple_get_bytes(buf, end, &id, sizeof(id));
 669         if (IS_ERR(p)) {
 670                 err = PTR_ERR(p);
 671                 goto err;
 672         }
 673
 674         uid = make_kuid(&init_user_ns, id);
 675         if (!uid_valid(uid)) {
 676                 err = -EINVAL;
 677                 goto err;
 678         }
 679
 680         err = -ENOMEM;
 681         ctx = gss_alloc_context();
 682         if (ctx == NULL)
 683                 goto err;
 684
 685         err = -ENOENT;
 686         /* Find a matching upcall */
 687         spin_lock(&pipe->lock);
 688         gss_msg = __gss_find_upcall(pipe, uid);
 689         if (gss_msg == NULL) {
 690                 spin_unlock(&pipe->lock);
 691                 goto err_put_ctx;
 692         }
 693         list_del_init(&gss_msg->list);
 694         spin_unlock(&pipe->lock);
 695
 696         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 697         if (IS_ERR(p)) {
 698                 err = PTR_ERR(p);
 699                 switch (err) {
 700                 case -EACCES:
 701                 case -EKEYEXPIRED:
 702                         gss_msg->msg.errno = err;
 703                         err = mlen;
 704                         break;
 705                 case -EFAULT:
 706                 case -ENOMEM:
 707                 case -EINVAL:
 708                 case -ENOSYS:
 709                         gss_msg->msg.errno = -EAGAIN;
 710                         break;
 711                 default:
 712                         printk(KERN_CRIT "%s: bad return from "
 713                                 "gss_fill_context: %zd\n", __func__, err);
 714                         BUG();
 715                 }
 716                 goto err_release_msg;
 717         }
 718         gss_msg->ctx = gss_get_ctx(ctx);
 719         err = mlen;
 720
 721 err_release_msg:
 722         spin_lock(&pipe->lock);
 723         __gss_unhash_msg(gss_msg);
 724         spin_unlock(&pipe->lock);
 725         gss_release_msg(gss_msg);
 726 err_put_ctx:
 727         gss_put_ctx(ctx);
 728 err:
 729         kfree(buf);
 730 out:
 731         dprintk("RPC:       %s returning %Zd\n", __func__, err);
 732         return err;
 733 }
 734
 735 static int gss_pipe_open(struct inode *inode, int new_version)
 736 {
 737         struct net *net = inode->i_sb->s_fs_info;
 738         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 739         int ret = 0;
 740
 741         spin_lock(&pipe_version_lock);
 742         if (sn->pipe_version < 0) {
 743                 /* First open of any gss pipe determines the version: */
 744                 sn->pipe_version = new_version;
 745                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 746                 wake_up(&pipe_version_waitqueue);
 747         } else if (sn->pipe_version != new_version) {
 748                 /* Trying to open a pipe of a different version */
 749                 ret = -EBUSY;
 750                 goto out;
 751         }
 752         atomic_inc(&sn->pipe_users);
 753 out:
 754         spin_unlock(&pipe_version_lock);
 755         return ret;
 756
 757 }
 758
 759 static int gss_pipe_open_v0(struct inode *inode)
 760 {
 761         return gss_pipe_open(inode, 0);
 762 }
 763
 764 static int gss_pipe_open_v1(struct inode *inode)
 765 {
 766         return gss_pipe_open(inode, 1);
 767 }
 768
 769 static void
 770 gss_pipe_release(struct inode *inode)
 771 {
 772         struct net *net = inode->i_sb->s_fs_info;
 773         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 774         struct gss_upcall_msg *gss_msg;
 775
 776 restart:
 777         spin_lock(&pipe->lock);
 778         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 779
 780                 if (!list_empty(&gss_msg->msg.list))
 781                         continue;
 782                 gss_msg->msg.errno = -EPIPE;
 783                 atomic_inc(&gss_msg->count);
 784                 __gss_unhash_msg(gss_msg);
 785                 spin_unlock(&pipe->lock);
 786                 gss_release_msg(gss_msg);
 787                 goto restart;
 788         }
 789         spin_unlock(&pipe->lock);
 790
 791         put_pipe_version(net);
 792 }
 793
 794 static void
 795 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 796 {
 797         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 798
 799         if (msg->errno < 0) {
 800                 dprintk("RPC:       %s releasing msg %p\n",
 801                         __func__, gss_msg);
 802                 atomic_inc(&gss_msg->count);
 803                 gss_unhash_msg(gss_msg);
 804                 if (msg->errno == -ETIMEDOUT)
 805                         warn_gssd();
 806                 gss_release_msg(gss_msg);
 807         }
 808 }
 809
 810 static void gss_pipe_dentry_destroy(struct dentry *dir,
 811                 struct rpc_pipe_dir_object *pdo)
 812 {
 813         struct gss_pipe *gss_pipe = pdo->pdo_data;
 814         struct rpc_pipe *pipe = gss_pipe->pipe;
 815
 816         if (pipe->dentry != NULL) {
 817                 rpc_unlink(pipe->dentry);
 818                 pipe->dentry = NULL;
 819         }
 820 }
 821
 822 static int gss_pipe_dentry_create(struct dentry *dir,
 823                 struct rpc_pipe_dir_object *pdo)
 824 {
 825         struct gss_pipe *p = pdo->pdo_data;
 826         struct dentry *dentry;
 827
 828         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 829         if (IS_ERR(dentry))
 830                 return PTR_ERR(dentry);
 831         p->pipe->dentry = dentry;
 832         return 0;
 833 }
 834
 835 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 836         .create = gss_pipe_dentry_create,
 837         .destroy = gss_pipe_dentry_destroy,
 838 };
 839
 840 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 841                 const char *name,
 842                 const struct rpc_pipe_ops *upcall_ops)
 843 {
 844         struct gss_pipe *p;
 845         int err = -ENOMEM;
 846
 847         p = kmalloc(sizeof(*p), GFP_KERNEL);
 848         if (p == NULL)
 849                 goto err;
 850         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 851         if (IS_ERR(p->pipe)) {
 852                 err = PTR_ERR(p->pipe);
 853                 goto err_free_gss_pipe;
 854         }
 855         p->name = name;
 856         p->clnt = clnt;
 857         kref_init(&p->kref);
 858         rpc_init_pipe_dir_object(&p->pdo,
 859                         &gss_pipe_dir_object_ops,
 860                         p);
 861         return p;
 862 err_free_gss_pipe:
 863         kfree(p);
 864 err:
 865         return ERR_PTR(err);
 866 }
 867
 868 struct gss_alloc_pdo {
 869         struct rpc_clnt *clnt;
 870         const char *name;
 871         const struct rpc_pipe_ops *upcall_ops;
 872 };
 873
 874 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 875 {
 876         struct gss_pipe *gss_pipe;
 877         struct gss_alloc_pdo *args = data;
 878
 879         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 880                 return 0;
 881         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 882         if (strcmp(gss_pipe->name, args->name) != 0)
 883                 return 0;
 884         if (!kref_get_unless_zero(&gss_pipe->kref))
 885                 return 0;
 886         return 1;
 887 }
 888
 889 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 890 {
 891         struct gss_pipe *gss_pipe;
 892         struct gss_alloc_pdo *args = data;
 893
 894         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 895         if (!IS_ERR(gss_pipe))
 896                 return &gss_pipe->pdo;
 897         return NULL;
 898 }
 899
 900 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 901                 const char *name,
 902                 const struct rpc_pipe_ops *upcall_ops)
 903 {
 904         struct net *net = rpc_net_ns(clnt);
 905         struct rpc_pipe_dir_object *pdo;
 906         struct gss_alloc_pdo args = {
 907                 .clnt = clnt,
 908                 .name = name,
 909                 .upcall_ops = upcall_ops,
 910         };
 911
 912         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 913                         &clnt->cl_pipedir_objects,
 914                         gss_pipe_match_pdo,
 915                         gss_pipe_alloc_pdo,
 916                         &args);
 917         if (pdo != NULL)
 918                 return container_of(pdo, struct gss_pipe, pdo);
 919         return ERR_PTR(-ENOMEM);
 920 }
 921
 922 static void __gss_pipe_free(struct gss_pipe *p)
 923 {
 924         struct rpc_clnt *clnt = p->clnt;
 925         struct net *net = rpc_net_ns(clnt);
 926
 927         rpc_remove_pipe_dir_object(net,
 928                         &clnt->cl_pipedir_objects,
 929                         &p->pdo);
 930         rpc_destroy_pipe_data(p->pipe);
 931         kfree(p);
 932 }
 933
 934 static void __gss_pipe_release(struct kref *kref)
 935 {
 936         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 937
 938         __gss_pipe_free(p);
 939 }
 940
 941 static void gss_pipe_free(struct gss_pipe *p)
 942 {
 943         if (p != NULL)
 944                 kref_put(&p->kref, __gss_pipe_release);
 945 }
 946
 947 /*
 948  * NOTE: we have the opportunity to use different
 949  * parameters based on the input flavor (which must be a pseudoflavor)
 950  */
 951 static struct gss_auth *
 952 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 953 {
 954         rpc_authflavor_t flavor = args->pseudoflavor;
 955         struct gss_auth *gss_auth;
 956         struct gss_pipe *gss_pipe;
 957         struct rpc_auth * auth;
 958         int err = -ENOMEM; /* XXX? */
 959
 960         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 961
 962         if (!try_module_get(THIS_MODULE))
 963                 return ERR_PTR(err);
 964         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 965                 goto out_dec;
 966         INIT_HLIST_NODE(&gss_auth->hash);
 967         gss_auth->target_name = NULL;
 968         if (args->target_name) {
 969                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
 970                 if (gss_auth->target_name == NULL)
 971                         goto err_free;
 972         }
 973         gss_auth->client = clnt;
 974         gss_auth->net = get_net(rpc_net_ns(clnt));
 975         err = -EINVAL;
 976         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 977         if (!gss_auth->mech) {
 978                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
 979                 goto err_put_net;
 980         }
 981         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 982         if (gss_auth->service == 0)
 983                 goto err_put_mech;
 984         auth = &gss_auth->rpc_auth;
 985         auth->au_cslack = GSS_CRED_SLACK >> 2;
 986         auth->au_rslack = GSS_VERF_SLACK >> 2;
 987         auth->au_ops = &authgss_ops;
 988         auth->au_flavor = flavor;
 989         atomic_set(&auth->au_count, 1);
 990         kref_init(&gss_auth->kref);
 991
 992         err = rpcauth_init_credcache(auth);
 993         if (err)
 994                 goto err_put_mech;
 995         /*
 996          * Note: if we created the old pipe first, then someone who
 997          * examined the directory at the right moment might conclude
 998          * that we supported only the old pipe.  So we instead create
 999          * the new pipe first.
1000          */
1001         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1002         if (IS_ERR(gss_pipe)) {
1003                 err = PTR_ERR(gss_pipe);
1004                 goto err_destroy_credcache;
1005         }
1006         gss_auth->gss_pipe[1] = gss_pipe;
1007
1008         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1009                         &gss_upcall_ops_v0);
1010         if (IS_ERR(gss_pipe)) {
1011                 err = PTR_ERR(gss_pipe);
1012                 goto err_destroy_pipe_1;
1013         }
1014         gss_auth->gss_pipe[0] = gss_pipe;
1015
1016         return gss_auth;
1017 err_destroy_pipe_1:
1018         gss_pipe_free(gss_auth->gss_pipe[1]);
1019 err_destroy_credcache:
1020         rpcauth_destroy_credcache(auth);
1021 err_put_mech:
1022         gss_mech_put(gss_auth->mech);
1023 err_put_net:
1024         put_net(gss_auth->net);
1025 err_free:
1026         kfree(gss_auth->target_name);
1027         kfree(gss_auth);
1028 out_dec:
1029         module_put(THIS_MODULE);
1030         return ERR_PTR(err);
1031 }
1032
1033 static void
1034 gss_free(struct gss_auth *gss_auth)
1035 {
1036         gss_pipe_free(gss_auth->gss_pipe[0]);
1037         gss_pipe_free(gss_auth->gss_pipe[1]);
1038         gss_mech_put(gss_auth->mech);
1039         put_net(gss_auth->net);
1040         kfree(gss_auth->target_name);
1041
1042         kfree(gss_auth);
1043         module_put(THIS_MODULE);
1044 }
1045
1046 static void
1047 gss_free_callback(struct kref *kref)
1048 {
1049         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1050
1051         gss_free(gss_auth);
1052 }
1053
1054 static void
1055 gss_destroy(struct rpc_auth *auth)
1056 {
1057         struct gss_auth *gss_auth = container_of(auth,
1058                         struct gss_auth, rpc_auth);
1059
1060         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1061                         auth, auth->au_flavor);
1062
1063         if (hash_hashed(&gss_auth->hash)) {
1064                 spin_lock(&gss_auth_hash_lock);
1065                 hash_del(&gss_auth->hash);
1066                 spin_unlock(&gss_auth_hash_lock);
1067         }
1068
1069         gss_pipe_free(gss_auth->gss_pipe[0]);
1070         gss_auth->gss_pipe[0] = NULL;
1071         gss_pipe_free(gss_auth->gss_pipe[1]);
1072         gss_auth->gss_pipe[1] = NULL;
1073         rpcauth_destroy_credcache(auth);
1074
1075         kref_put(&gss_auth->kref, gss_free_callback);
1076 }
1077
1078 /*
1079  * Auths may be shared between rpc clients that were cloned from a
1080  * common client with the same xprt, if they also share the flavor and
1081  * target_name.
1082  *
1083  * The auth is looked up from the oldest parent sharing the same
1084  * cl_xprt, and the auth itself references only that common parent
1085  * (which is guaranteed to last as long as any of its descendants).
1086  */
1087 static struct gss_auth *
1088 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1089                 struct rpc_clnt *clnt,
1090                 struct gss_auth *new)
1091 {
1092         struct gss_auth *gss_auth;
1093         unsigned long hashval = (unsigned long)clnt;
1094
1095         spin_lock(&gss_auth_hash_lock);
1096         hash_for_each_possible(gss_auth_hash_table,
1097                         gss_auth,
1098                         hash,
1099                         hashval) {
1100                 if (gss_auth->client != clnt)
1101                         continue;
1102                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1103                         continue;
1104                 if (gss_auth->target_name != args->target_name) {
1105                         if (gss_auth->target_name == NULL)
1106                                 continue;
1107                         if (args->target_name == NULL)
1108                                 continue;
1109                         if (strcmp(gss_auth->target_name, args->target_name))
1110                                 continue;
1111                 }
1112                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1113                         continue;
1114                 goto out;
1115         }
1116         if (new)
1117                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1118         gss_auth = new;
1119 out:
1120         spin_unlock(&gss_auth_hash_lock);
1121         return gss_auth;
1122 }
1123
1124 static struct gss_auth *
1125 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1126 {
1127         struct gss_auth *gss_auth;
1128         struct gss_auth *new;
1129
1130         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1131         if (gss_auth != NULL)
1132                 goto out;
1133         new = gss_create_new(args, clnt);
1134         if (IS_ERR(new))
1135                 return new;
1136         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1137         if (gss_auth != new)
1138                 gss_destroy(&new->rpc_auth);
1139 out:
1140         return gss_auth;
1141 }
1142
1143 static struct rpc_auth *
1144 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1145 {
1146         struct gss_auth *gss_auth;
1147         struct rpc_xprt *xprt = rcu_access_pointer(clnt->cl_xprt);
1148
1149         while (clnt != clnt->cl_parent) {
1150                 struct rpc_clnt *parent = clnt->cl_parent;
1151                 /* Find the original parent for this transport */
1152                 if (rcu_access_pointer(parent->cl_xprt) != xprt)
1153                         break;
1154                 clnt = parent;
1155         }
1156
1157         gss_auth = gss_create_hashed(args, clnt);
1158         if (IS_ERR(gss_auth))
1159                 return ERR_CAST(gss_auth);
1160         return &gss_auth->rpc_auth;
1161 }
1162
1163 /*
1164  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1165  * to the server with the GSS control procedure field set to
1166  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1167  * all RPCSEC_GSS state associated with that context.
1168  */
1169 static int
1170 gss_destroying_context(struct rpc_cred *cred)
1171 {
1172         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1173         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1174         struct rpc_task *task;
1175
1176         if (gss_cred->gc_ctx == NULL ||
1177             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1178                 return 0;
1179
1180         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1181         cred->cr_ops = &gss_nullops;
1182
1183         /* Take a reference to ensure the cred will be destroyed either
1184          * by the RPC call or by the put_rpccred() below */
1185         get_rpccred(cred);
1186
1187         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1188         if (!IS_ERR(task))
1189                 rpc_put_task(task);
1190
1191         put_rpccred(cred);
1192         return 1;
1193 }
1194
1195 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1196  * to create a new cred or context, so they check that things have been
1197  * allocated before freeing them. */
1198 static void
1199 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1200 {
1201         dprintk("RPC:       %s\n", __func__);
1202
1203         gss_delete_sec_context(&ctx->gc_gss_ctx);
1204         kfree(ctx->gc_wire_ctx.data);
1205         kfree(ctx);
1206 }
1207
1208 static void
1209 gss_free_ctx_callback(struct rcu_head *head)
1210 {
1211         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1212         gss_do_free_ctx(ctx);
1213 }
1214
1215 static void
1216 gss_free_ctx(struct gss_cl_ctx *ctx)
1217 {
1218         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1219 }
1220
1221 static void
1222 gss_free_cred(struct gss_cred *gss_cred)
1223 {
1224         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1225         kfree(gss_cred);
1226 }
1227
1228 static void
1229 gss_free_cred_callback(struct rcu_head *head)
1230 {
1231         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1232         gss_free_cred(gss_cred);
1233 }
1234
1235 static void
1236 gss_destroy_nullcred(struct rpc_cred *cred)
1237 {
1238         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1239         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1240         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
1241
1242         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1243         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1244         if (ctx)
1245                 gss_put_ctx(ctx);
1246         kref_put(&gss_auth->kref, gss_free_callback);
1247 }
1248
1249 static void
1250 gss_destroy_cred(struct rpc_cred *cred)
1251 {
1252
1253         if (gss_destroying_context(cred))
1254                 return;
1255         gss_destroy_nullcred(cred);
1256 }
1257
1258 /*
1259  * Lookup RPCSEC_GSS cred for the current process
1260  */
1261 static struct rpc_cred *
1262 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1263 {
1264         return rpcauth_lookup_credcache(auth, acred, flags);
1265 }
1266
1267 static struct rpc_cred *
1268 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1269 {
1270         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1271         struct gss_cred *cred = NULL;
1272         int err = -ENOMEM;
1273
1274         dprintk("RPC:       %s for uid %d, flavor %d\n",
1275                 __func__, from_kuid(&init_user_ns, acred->uid),
1276                 auth->au_flavor);
1277
1278         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1279                 goto out_err;
1280
1281         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1282         /*
1283          * Note: in order to force a call to call_refresh(), we deliberately
1284          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1285          */
1286         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1287         cred->gc_service = gss_auth->service;
1288         cred->gc_principal = NULL;
1289         if (acred->machine_cred)
1290                 cred->gc_principal = acred->principal;
1291         kref_get(&gss_auth->kref);
1292         return &cred->gc_base;
1293
1294 out_err:
1295         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1296         return ERR_PTR(err);
1297 }
1298
1299 static int
1300 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1301 {
1302         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1303         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1304         int err;
1305
1306         do {
1307                 err = gss_create_upcall(gss_auth, gss_cred);
1308         } while (err == -EAGAIN);
1309         return err;
1310 }
1311
1312 /*
1313  * Returns -EACCES if GSS context is NULL or will expire within the
1314  * timeout (miliseconds)
1315  */
1316 static int
1317 gss_key_timeout(struct rpc_cred *rc)
1318 {
1319         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1320         unsigned long now = jiffies;
1321         unsigned long expire;
1322
1323         if (gss_cred->gc_ctx == NULL)
1324                 return -EACCES;
1325
1326         expire = gss_cred->gc_ctx->gc_expiry - (gss_key_expire_timeo * HZ);
1327
1328         if (time_after(now, expire))
1329                 return -EACCES;
1330         return 0;
1331 }
1332
1333 static int
1334 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1335 {
1336         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1337         int ret;
1338
1339         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1340                 goto out;
1341         /* Don't match with creds that have expired. */
1342         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1343                 return 0;
1344         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1345                 return 0;
1346 out:
1347         if (acred->principal != NULL) {
1348                 if (gss_cred->gc_principal == NULL)
1349                         return 0;
1350                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1351                 goto check_expire;
1352         }
1353         if (gss_cred->gc_principal != NULL)
1354                 return 0;
1355         ret = uid_eq(rc->cr_uid, acred->uid);
1356
1357 check_expire:
1358         if (ret == 0)
1359                 return ret;
1360
1361         /* Notify acred users of GSS context expiration timeout */
1362         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1363             (gss_key_timeout(rc) != 0)) {
1364                 /* test will now be done from generic cred */
1365                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1366                 /* tell NFS layer that key will expire soon */
1367                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1368         }
1369         return ret;
1370 }
1371
1372 /*
1373 * Marshal credentials.
1374 * Maybe we should keep a cached credential for performance reasons.
1375 */
1376 static __be32 *
1377 gss_marshal(struct rpc_task *task, __be32 *p)
1378 {
1379         struct rpc_rqst *req = task->tk_rqstp;
1380         struct rpc_cred *cred = req->rq_cred;
1381         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1382                                                  gc_base);
1383         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1384         __be32          *cred_len;
1385         u32             maj_stat = 0;
1386         struct xdr_netobj mic;
1387         struct kvec     iov;
1388         struct xdr_buf  verf_buf;
1389
1390         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1391
1392         *p++ = htonl(RPC_AUTH_GSS);
1393         cred_len = p++;
1394
1395         spin_lock(&ctx->gc_seq_lock);
1396         req->rq_seqno = ctx->gc_seq++;
1397         spin_unlock(&ctx->gc_seq_lock);
1398
1399         *p++ = htonl((u32) RPC_GSS_VERSION);
1400         *p++ = htonl((u32) ctx->gc_proc);
1401         *p++ = htonl((u32) req->rq_seqno);
1402         *p++ = htonl((u32) gss_cred->gc_service);
1403         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1404         *cred_len = htonl((p - (cred_len + 1)) << 2);
1405
1406         /* We compute the checksum for the verifier over the xdr-encoded bytes
1407          * starting with the xid and ending at the end of the credential: */
1408         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1409                                         req->rq_snd_buf.head[0].iov_base);
1410         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1411         xdr_buf_from_iov(&iov, &verf_buf);
1412
1413         /* set verifier flavor*/
1414         *p++ = htonl(RPC_AUTH_GSS);
1415
1416         mic.data = (u8 *)(p + 1);
1417         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1418         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1419                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1420         } else if (maj_stat != 0) {
1421                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1422                 goto out_put_ctx;
1423         }
1424         p = xdr_encode_opaque(p, NULL, mic.len);
1425         gss_put_ctx(ctx);
1426         return p;
1427 out_put_ctx:
1428         gss_put_ctx(ctx);
1429         return NULL;
1430 }
1431
1432 static int gss_renew_cred(struct rpc_task *task)
1433 {
1434         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1435         struct gss_cred *gss_cred = container_of(oldcred,
1436                                                  struct gss_cred,
1437                                                  gc_base);
1438         struct rpc_auth *auth = oldcred->cr_auth;
1439         struct auth_cred acred = {
1440                 .uid = oldcred->cr_uid,
1441                 .principal = gss_cred->gc_principal,
1442                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1443         };
1444         struct rpc_cred *new;
1445
1446         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1447         if (IS_ERR(new))
1448                 return PTR_ERR(new);
1449         task->tk_rqstp->rq_cred = new;
1450         put_rpccred(oldcred);
1451         return 0;
1452 }
1453
1454 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1455 {
1456         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1457                 unsigned long now = jiffies;
1458                 unsigned long begin, expire;
1459                 struct gss_cred *gss_cred;
1460
1461                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1462                 begin = gss_cred->gc_upcall_timestamp;
1463                 expire = begin + gss_expired_cred_retry_delay * HZ;
1464
1465                 if (time_in_range_open(now, begin, expire))
1466                         return 1;
1467         }
1468         return 0;
1469 }
1470
1471 /*
1472 * Refresh credentials. XXX - finish
1473 */
1474 static int
1475 gss_refresh(struct rpc_task *task)
1476 {
1477         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1478         int ret = 0;
1479
1480         if (gss_cred_is_negative_entry(cred))
1481                 return -EKEYEXPIRED;
1482
1483         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1484                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1485                 ret = gss_renew_cred(task);
1486                 if (ret < 0)
1487                         goto out;
1488                 cred = task->tk_rqstp->rq_cred;
1489         }
1490
1491         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1492                 ret = gss_refresh_upcall(task);
1493 out:
1494         return ret;
1495 }
1496
1497 /* Dummy refresh routine: used only when destroying the context */
1498 static int
1499 gss_refresh_null(struct rpc_task *task)
1500 {
1501         return -EACCES;
1502 }
1503
1504 static __be32 *
1505 gss_validate(struct rpc_task *task, __be32 *p)
1506 {
1507         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1508         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1509         __be32          seq;
1510         struct kvec     iov;
1511         struct xdr_buf  verf_buf;
1512         struct xdr_netobj mic;
1513         u32             flav,len;
1514         u32             maj_stat;
1515         __be32          *ret = ERR_PTR(-EIO);
1516
1517         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1518
1519         flav = ntohl(*p++);
1520         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1521                 goto out_bad;
1522         if (flav != RPC_AUTH_GSS)
1523                 goto out_bad;
1524         seq = htonl(task->tk_rqstp->rq_seqno);
1525         iov.iov_base = &seq;
1526         iov.iov_len = sizeof(seq);
1527         xdr_buf_from_iov(&iov, &verf_buf);
1528         mic.data = (u8 *)p;
1529         mic.len = len;
1530
1531         ret = ERR_PTR(-EACCES);
1532         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1533         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1534                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1535         if (maj_stat) {
1536                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1537                         task->tk_pid, __func__, maj_stat);
1538                 goto out_bad;
1539         }
1540         /* We leave it to unwrap to calculate au_rslack. For now we just
1541          * calculate the length of the verifier: */
1542         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1543         gss_put_ctx(ctx);
1544         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1545                         task->tk_pid, __func__);
1546         return p + XDR_QUADLEN(len);
1547 out_bad:
1548         gss_put_ctx(ctx);
1549         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1550                 PTR_ERR(ret));
1551         return ret;
1552 }
1553
1554 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1555                                 __be32 *p, void *obj)
1556 {
1557         struct xdr_stream xdr;
1558
1559         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1560         encode(rqstp, &xdr, obj);
1561 }
1562
1563 static inline int
1564 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1565                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1566                    __be32 *p, void *obj)
1567 {
1568         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1569         struct xdr_buf  integ_buf;
1570         __be32          *integ_len = NULL;
1571         struct xdr_netobj mic;
1572         u32             offset;
1573         __be32          *q;
1574         struct kvec     *iov;
1575         u32             maj_stat = 0;
1576         int             status = -EIO;
1577
1578         integ_len = p++;
1579         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1580         *p++ = htonl(rqstp->rq_seqno);
1581
1582         gss_wrap_req_encode(encode, rqstp, p, obj);
1583
1584         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1585                                 offset, snd_buf->len - offset))
1586                 return status;
1587         *integ_len = htonl(integ_buf.len);
1588
1589         /* guess whether we're in the head or the tail: */
1590         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1591                 iov = snd_buf->tail;
1592         else
1593                 iov = snd_buf->head;
1594         p = iov->iov_base + iov->iov_len;
1595         mic.data = (u8 *)(p + 1);
1596
1597         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1598         status = -EIO; /* XXX? */
1599         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1600                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1601         else if (maj_stat)
1602                 return status;
1603         q = xdr_encode_opaque(p, NULL, mic.len);
1604
1605         offset = (u8 *)q - (u8 *)p;
1606         iov->iov_len += offset;
1607         snd_buf->len += offset;
1608         return 0;
1609 }
1610
1611 static void
1612 priv_release_snd_buf(struct rpc_rqst *rqstp)
1613 {
1614         int i;
1615
1616         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1617                 __free_page(rqstp->rq_enc_pages[i]);
1618         kfree(rqstp->rq_enc_pages);
1619 }
1620
1621 static int
1622 alloc_enc_pages(struct rpc_rqst *rqstp)
1623 {
1624         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1625         int first, last, i;
1626
1627         if (snd_buf->page_len == 0) {
1628                 rqstp->rq_enc_pages_num = 0;
1629                 return 0;
1630         }
1631
1632         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1633         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1634         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1635         rqstp->rq_enc_pages
1636                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1637                                 GFP_NOFS);
1638         if (!rqstp->rq_enc_pages)
1639                 goto out;
1640         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1641                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1642                 if (rqstp->rq_enc_pages[i] == NULL)
1643                         goto out_free;
1644         }
1645         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1646         return 0;
1647 out_free:
1648         rqstp->rq_enc_pages_num = i;
1649         priv_release_snd_buf(rqstp);
1650 out:
1651         return -EAGAIN;
1652 }
1653
1654 static inline int
1655 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1656                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1657                   __be32 *p, void *obj)
1658 {
1659         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1660         u32             offset;
1661         u32             maj_stat;
1662         int             status;
1663         __be32          *opaque_len;
1664         struct page     **inpages;
1665         int             first;
1666         int             pad;
1667         struct kvec     *iov;
1668         char            *tmp;
1669
1670         opaque_len = p++;
1671         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1672         *p++ = htonl(rqstp->rq_seqno);
1673
1674         gss_wrap_req_encode(encode, rqstp, p, obj);
1675
1676         status = alloc_enc_pages(rqstp);
1677         if (status)
1678                 return status;
1679         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1680         inpages = snd_buf->pages + first;
1681         snd_buf->pages = rqstp->rq_enc_pages;
1682         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1683         /*
1684          * Give the tail its own page, in case we need extra space in the
1685          * head when wrapping:
1686          *
1687          * call_allocate() allocates twice the slack space required
1688          * by the authentication flavor to rq_callsize.
1689          * For GSS, slack is GSS_CRED_SLACK.
1690          */
1691         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1692                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1693                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1694                 snd_buf->tail[0].iov_base = tmp;
1695         }
1696         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1697         /* slack space should prevent this ever happening: */
1698         BUG_ON(snd_buf->len > snd_buf->buflen);
1699         status = -EIO;
1700         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1701          * done anyway, so it's safe to put the request on the wire: */
1702         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1703                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1704         else if (maj_stat)
1705                 return status;
1706
1707         *opaque_len = htonl(snd_buf->len - offset);
1708         /* guess whether we're in the head or the tail: */
1709         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1710                 iov = snd_buf->tail;
1711         else
1712                 iov = snd_buf->head;
1713         p = iov->iov_base + iov->iov_len;
1714         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1715         memset(p, 0, pad);
1716         iov->iov_len += pad;
1717         snd_buf->len += pad;
1718
1719         return 0;
1720 }
1721
1722 static int
1723 gss_wrap_req(struct rpc_task *task,
1724              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1725 {
1726         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1727         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1728                         gc_base);
1729         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1730         int             status = -EIO;
1731
1732         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1733         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1734                 /* The spec seems a little ambiguous here, but I think that not
1735                  * wrapping context destruction requests makes the most sense.
1736                  */
1737                 gss_wrap_req_encode(encode, rqstp, p, obj);
1738                 status = 0;
1739                 goto out;
1740         }
1741         switch (gss_cred->gc_service) {
1742         case RPC_GSS_SVC_NONE:
1743                 gss_wrap_req_encode(encode, rqstp, p, obj);
1744                 status = 0;
1745                 break;
1746         case RPC_GSS_SVC_INTEGRITY:
1747                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1748                 break;
1749         case RPC_GSS_SVC_PRIVACY:
1750                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1751                 break;
1752         }
1753 out:
1754         gss_put_ctx(ctx);
1755         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1756         return status;
1757 }
1758
1759 static inline int
1760 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1761                 struct rpc_rqst *rqstp, __be32 **p)
1762 {
1763         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1764         struct xdr_buf integ_buf;
1765         struct xdr_netobj mic;
1766         u32 data_offset, mic_offset;
1767         u32 integ_len;
1768         u32 maj_stat;
1769         int status = -EIO;
1770
1771         integ_len = ntohl(*(*p)++);
1772         if (integ_len & 3)
1773                 return status;
1774         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1775         mic_offset = integ_len + data_offset;
1776         if (mic_offset > rcv_buf->len)
1777                 return status;
1778         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1779                 return status;
1780
1781         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1782                                 mic_offset - data_offset))
1783                 return status;
1784
1785         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1786                 return status;
1787
1788         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1789         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1790                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1791         if (maj_stat != GSS_S_COMPLETE)
1792                 return status;
1793         return 0;
1794 }
1795
1796 static inline int
1797 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1798                 struct rpc_rqst *rqstp, __be32 **p)
1799 {
1800         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1801         u32 offset;
1802         u32 opaque_len;
1803         u32 maj_stat;
1804         int status = -EIO;
1805
1806         opaque_len = ntohl(*(*p)++);
1807         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1808         if (offset + opaque_len > rcv_buf->len)
1809                 return status;
1810         /* remove padding: */
1811         rcv_buf->len = offset + opaque_len;
1812
1813         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1814         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1815                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1816         if (maj_stat != GSS_S_COMPLETE)
1817                 return status;
1818         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1819                 return status;
1820
1821         return 0;
1822 }
1823
1824 static int
1825 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1826                       __be32 *p, void *obj)
1827 {
1828         struct xdr_stream xdr;
1829
1830         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1831         return decode(rqstp, &xdr, obj);
1832 }
1833
1834 static int
1835 gss_unwrap_resp(struct rpc_task *task,
1836                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1837 {
1838         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1839         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1840                         gc_base);
1841         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1842         __be32          *savedp = p;
1843         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1844         int             savedlen = head->iov_len;
1845         int             status = -EIO;
1846
1847         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1848                 goto out_decode;
1849         switch (gss_cred->gc_service) {
1850         case RPC_GSS_SVC_NONE:
1851                 break;
1852         case RPC_GSS_SVC_INTEGRITY:
1853                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1854                 if (status)
1855                         goto out;
1856                 break;
1857         case RPC_GSS_SVC_PRIVACY:
1858                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1859                 if (status)
1860                         goto out;
1861                 break;
1862         }
1863         /* take into account extra slack for integrity and privacy cases: */
1864         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1865                                                 + (savedlen - head->iov_len);
1866 out_decode:
1867         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1868 out:
1869         gss_put_ctx(ctx);
1870         dprintk("RPC: %5u %s returning %d\n",
1871                 task->tk_pid, __func__, status);
1872         return status;
1873 }
1874
1875 static const struct rpc_authops authgss_ops = {
1876         .owner          = THIS_MODULE,
1877         .au_flavor      = RPC_AUTH_GSS,
1878         .au_name        = "RPCSEC_GSS",
1879         .create         = gss_create,
1880         .destroy        = gss_destroy,
1881         .lookup_cred    = gss_lookup_cred,
1882         .crcreate       = gss_create_cred,
1883         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1884         .info2flavor    = gss_mech_info2flavor,
1885         .flavor2info    = gss_mech_flavor2info,
1886 };
1887
1888 static const struct rpc_credops gss_credops = {
1889         .cr_name        = "AUTH_GSS",
1890         .crdestroy      = gss_destroy_cred,
1891         .cr_init        = gss_cred_init,
1892         .crbind         = rpcauth_generic_bind_cred,
1893         .crmatch        = gss_match,
1894         .crmarshal      = gss_marshal,
1895         .crrefresh      = gss_refresh,
1896         .crvalidate     = gss_validate,
1897         .crwrap_req     = gss_wrap_req,
1898         .crunwrap_resp  = gss_unwrap_resp,
1899         .crkey_timeout  = gss_key_timeout,
1900 };
1901
1902 static const struct rpc_credops gss_nullops = {
1903         .cr_name        = "AUTH_GSS",
1904         .crdestroy      = gss_destroy_nullcred,
1905         .crbind         = rpcauth_generic_bind_cred,
1906         .crmatch        = gss_match,
1907         .crmarshal      = gss_marshal,
1908         .crrefresh      = gss_refresh_null,
1909         .crvalidate     = gss_validate,
1910         .crwrap_req     = gss_wrap_req,
1911         .crunwrap_resp  = gss_unwrap_resp,
1912 };
1913
1914 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1915         .upcall         = rpc_pipe_generic_upcall,
1916         .downcall       = gss_pipe_downcall,
1917         .destroy_msg    = gss_pipe_destroy_msg,
1918         .open_pipe      = gss_pipe_open_v0,
1919         .release_pipe   = gss_pipe_release,
1920 };
1921
1922 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1923         .upcall         = rpc_pipe_generic_upcall,
1924         .downcall       = gss_pipe_downcall,
1925         .destroy_msg    = gss_pipe_destroy_msg,
1926         .open_pipe      = gss_pipe_open_v1,
1927         .release_pipe   = gss_pipe_release,
1928 };
1929
1930 static __net_init int rpcsec_gss_init_net(struct net *net)
1931 {
1932         return gss_svc_init_net(net);
1933 }
1934
1935 static __net_exit void rpcsec_gss_exit_net(struct net *net)
1936 {
1937         gss_svc_shutdown_net(net);
1938 }
1939
1940 static struct pernet_operations rpcsec_gss_net_ops = {
1941         .init = rpcsec_gss_init_net,
1942         .exit = rpcsec_gss_exit_net,
1943 };
1944
1945 /*
1946  * Initialize RPCSEC_GSS module
1947  */
1948 static int __init init_rpcsec_gss(void)
1949 {
1950         int err = 0;
1951
1952         err = rpcauth_register(&authgss_ops);
1953         if (err)
1954                 goto out;
1955         err = gss_svc_init();
1956         if (err)
1957                 goto out_unregister;
1958         err = register_pernet_subsys(&rpcsec_gss_net_ops);
1959         if (err)
1960                 goto out_svc_exit;
1961         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1962         return 0;
1963 out_svc_exit:
1964         gss_svc_shutdown();
1965 out_unregister:
1966         rpcauth_unregister(&authgss_ops);
1967 out:
1968         return err;
1969 }
1970
1971 static void __exit exit_rpcsec_gss(void)
1972 {
1973         unregister_pernet_subsys(&rpcsec_gss_net_ops);
1974         gss_svc_shutdown();
1975         rpcauth_unregister(&authgss_ops);
1976         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1977 }
1978
1979 MODULE_ALIAS("rpc-auth-6");
1980 MODULE_LICENSE("GPL");
1981 module_param_named(expired_cred_retry_delay,
1982                    gss_expired_cred_retry_delay,
1983                    uint, 0644);
1984 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
1985                 "the RPC engine retries an expired credential");
1986
1987 module_param_named(key_expire_timeo,
1988                    gss_key_expire_timeo,
1989                    uint, 0644);
1990 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
1991                 "credential keys lifetime where the NFS layer cleans up "
1992                 "prior to key expiration");
1993
1994 module_init(init_rpcsec_gss)
1995 module_exit(exit_rpcsec_gss)