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                 break;
 486         default:
 487                 gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
 488         };
 489         return gss_msg;
 490 }
 491
 492 static struct gss_upcall_msg *
 493 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 494 {
 495         struct gss_cred *gss_cred = container_of(cred,
 496                         struct gss_cred, gc_base);
 497         struct gss_upcall_msg *gss_new, *gss_msg;
 498         kuid_t uid = cred->cr_uid;
 499
 500         gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 501         if (IS_ERR(gss_new))
 502                 return gss_new;
 503         gss_msg = gss_add_msg(gss_new);
 504         if (gss_msg == gss_new) {
 505                 int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 506                 if (res) {
 507                         gss_unhash_msg(gss_new);
 508                         gss_msg = ERR_PTR(res);
 509                 }
 510         } else
 511                 gss_release_msg(gss_new);
 512         return gss_msg;
 513 }
 514
 515 static void warn_gssd(void)
 516 {
 517         static unsigned long ratelimit;
 518         unsigned long now = jiffies;
 519
 520         if (time_after(now, ratelimit)) {
 521                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 522                                 "Please check user daemon is running.\n");
 523                 ratelimit = now + 15*HZ;
 524         }
 525 }
 526
 527 static inline int
 528 gss_refresh_upcall(struct rpc_task *task)
 529 {
 530         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 531         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 532                         struct gss_auth, rpc_auth);
 533         struct gss_cred *gss_cred = container_of(cred,
 534                         struct gss_cred, gc_base);
 535         struct gss_upcall_msg *gss_msg;
 536         struct rpc_pipe *pipe;
 537         int err = 0;
 538
 539         dprintk("RPC: %5u %s for uid %u\n",
 540                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 541         gss_msg = gss_setup_upcall(gss_auth, cred);
 542         if (PTR_ERR(gss_msg) == -EAGAIN) {
 543                 /* XXX: warning on the first, under the assumption we
 544                  * shouldn't normally hit this case on a refresh. */
 545                 warn_gssd();
 546                 task->tk_timeout = 15*HZ;
 547                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 548                 return -EAGAIN;
 549         }
 550         if (IS_ERR(gss_msg)) {
 551                 err = PTR_ERR(gss_msg);
 552                 goto out;
 553         }
 554         pipe = gss_msg->pipe;
 555         spin_lock(&pipe->lock);
 556         if (gss_cred->gc_upcall != NULL)
 557                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 558         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 559                 task->tk_timeout = 0;
 560                 gss_cred->gc_upcall = gss_msg;
 561                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 562                 atomic_inc(&gss_msg->count);
 563                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 564         } else {
 565                 gss_handle_downcall_result(gss_cred, gss_msg);
 566                 err = gss_msg->msg.errno;
 567         }
 568         spin_unlock(&pipe->lock);
 569         gss_release_msg(gss_msg);
 570 out:
 571         dprintk("RPC: %5u %s for uid %u result %d\n",
 572                 task->tk_pid, __func__,
 573                 from_kuid(&init_user_ns, cred->cr_uid), err);
 574         return err;
 575 }
 576
 577 static inline int
 578 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 579 {
 580         struct net *net = gss_auth->net;
 581         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 582         struct rpc_pipe *pipe;
 583         struct rpc_cred *cred = &gss_cred->gc_base;
 584         struct gss_upcall_msg *gss_msg;
 585         unsigned long timeout;
 586         DEFINE_WAIT(wait);
 587         int err;
 588
 589         dprintk("RPC:       %s for uid %u\n",
 590                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 591 retry:
 592         err = 0;
 593         /* Default timeout is 15s unless we know that gssd is not running */
 594         timeout = 15 * HZ;
 595         if (!sn->gssd_running)
 596                 timeout = HZ >> 2;
 597         gss_msg = gss_setup_upcall(gss_auth, cred);
 598         if (PTR_ERR(gss_msg) == -EAGAIN) {
 599                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 600                                 sn->pipe_version >= 0, timeout);
 601                 if (sn->pipe_version < 0) {
 602                         if (err == 0)
 603                                 sn->gssd_running = 0;
 604                         warn_gssd();
 605                         err = -EACCES;
 606                 }
 607                 if (err < 0)
 608                         goto out;
 609                 goto retry;
 610         }
 611         if (IS_ERR(gss_msg)) {
 612                 err = PTR_ERR(gss_msg);
 613                 goto out;
 614         }
 615         pipe = gss_msg->pipe;
 616         for (;;) {
 617                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 618                 spin_lock(&pipe->lock);
 619                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 620                         break;
 621                 }
 622                 spin_unlock(&pipe->lock);
 623                 if (fatal_signal_pending(current)) {
 624                         err = -ERESTARTSYS;
 625                         goto out_intr;
 626                 }
 627                 schedule();
 628         }
 629         if (gss_msg->ctx)
 630                 gss_cred_set_ctx(cred, gss_msg->ctx);
 631         else
 632                 err = gss_msg->msg.errno;
 633         spin_unlock(&pipe->lock);
 634 out_intr:
 635         finish_wait(&gss_msg->waitqueue, &wait);
 636         gss_release_msg(gss_msg);
 637 out:
 638         dprintk("RPC:       %s for uid %u result %d\n",
 639                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 640         return err;
 641 }
 642
 643 #define MSG_BUF_MAXSIZE 1024
 644
 645 static ssize_t
 646 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 647 {
 648         const void *p, *end;
 649         void *buf;
 650         struct gss_upcall_msg *gss_msg;
 651         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 652         struct gss_cl_ctx *ctx;
 653         uid_t id;
 654         kuid_t uid;
 655         ssize_t err = -EFBIG;
 656
 657         if (mlen > MSG_BUF_MAXSIZE)
 658                 goto out;
 659         err = -ENOMEM;
 660         buf = kmalloc(mlen, GFP_NOFS);
 661         if (!buf)
 662                 goto out;
 663
 664         err = -EFAULT;
 665         if (copy_from_user(buf, src, mlen))
 666                 goto err;
 667
 668         end = (const void *)((char *)buf + mlen);
 669         p = simple_get_bytes(buf, end, &id, sizeof(id));
 670         if (IS_ERR(p)) {
 671                 err = PTR_ERR(p);
 672                 goto err;
 673         }
 674
 675         uid = make_kuid(&init_user_ns, id);
 676         if (!uid_valid(uid)) {
 677                 err = -EINVAL;
 678                 goto err;
 679         }
 680
 681         err = -ENOMEM;
 682         ctx = gss_alloc_context();
 683         if (ctx == NULL)
 684                 goto err;
 685
 686         err = -ENOENT;
 687         /* Find a matching upcall */
 688         spin_lock(&pipe->lock);
 689         gss_msg = __gss_find_upcall(pipe, uid);
 690         if (gss_msg == NULL) {
 691                 spin_unlock(&pipe->lock);
 692                 goto err_put_ctx;
 693         }
 694         list_del_init(&gss_msg->list);
 695         spin_unlock(&pipe->lock);
 696
 697         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 698         if (IS_ERR(p)) {
 699                 err = PTR_ERR(p);
 700                 switch (err) {
 701                 case -EACCES:
 702                 case -EKEYEXPIRED:
 703                         gss_msg->msg.errno = err;
 704                         err = mlen;
 705                         break;
 706                 case -EFAULT:
 707                 case -ENOMEM:
 708                 case -EINVAL:
 709                 case -ENOSYS:
 710                         gss_msg->msg.errno = -EAGAIN;
 711                         break;
 712                 default:
 713                         printk(KERN_CRIT "%s: bad return from "
 714                                 "gss_fill_context: %zd\n", __func__, err);
 715                         BUG();
 716                 }
 717                 goto err_release_msg;
 718         }
 719         gss_msg->ctx = gss_get_ctx(ctx);
 720         err = mlen;
 721
 722 err_release_msg:
 723         spin_lock(&pipe->lock);
 724         __gss_unhash_msg(gss_msg);
 725         spin_unlock(&pipe->lock);
 726         gss_release_msg(gss_msg);
 727 err_put_ctx:
 728         gss_put_ctx(ctx);
 729 err:
 730         kfree(buf);
 731 out:
 732         dprintk("RPC:       %s returning %Zd\n", __func__, err);
 733         return err;
 734 }
 735
 736 static int gss_pipe_open(struct inode *inode, int new_version)
 737 {
 738         struct net *net = inode->i_sb->s_fs_info;
 739         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 740         int ret = 0;
 741
 742         spin_lock(&pipe_version_lock);
 743         if (sn->pipe_version < 0) {
 744                 /* First open of any gss pipe determines the version: */
 745                 sn->pipe_version = new_version;
 746                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 747                 wake_up(&pipe_version_waitqueue);
 748         } else if (sn->pipe_version != new_version) {
 749                 /* Trying to open a pipe of a different version */
 750                 ret = -EBUSY;
 751                 goto out;
 752         }
 753         atomic_inc(&sn->pipe_users);
 754 out:
 755         spin_unlock(&pipe_version_lock);
 756         return ret;
 757
 758 }
 759
 760 static int gss_pipe_open_v0(struct inode *inode)
 761 {
 762         return gss_pipe_open(inode, 0);
 763 }
 764
 765 static int gss_pipe_open_v1(struct inode *inode)
 766 {
 767         return gss_pipe_open(inode, 1);
 768 }
 769
 770 static void
 771 gss_pipe_release(struct inode *inode)
 772 {
 773         struct net *net = inode->i_sb->s_fs_info;
 774         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 775         struct gss_upcall_msg *gss_msg;
 776
 777 restart:
 778         spin_lock(&pipe->lock);
 779         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 780
 781                 if (!list_empty(&gss_msg->msg.list))
 782                         continue;
 783                 gss_msg->msg.errno = -EPIPE;
 784                 atomic_inc(&gss_msg->count);
 785                 __gss_unhash_msg(gss_msg);
 786                 spin_unlock(&pipe->lock);
 787                 gss_release_msg(gss_msg);
 788                 goto restart;
 789         }
 790         spin_unlock(&pipe->lock);
 791
 792         put_pipe_version(net);
 793 }
 794
 795 static void
 796 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 797 {
 798         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 799
 800         if (msg->errno < 0) {
 801                 dprintk("RPC:       %s releasing msg %p\n",
 802                         __func__, gss_msg);
 803                 atomic_inc(&gss_msg->count);
 804                 gss_unhash_msg(gss_msg);
 805                 if (msg->errno == -ETIMEDOUT)
 806                         warn_gssd();
 807                 gss_release_msg(gss_msg);
 808         }
 809 }
 810
 811 static void gss_pipe_dentry_destroy(struct dentry *dir,
 812                 struct rpc_pipe_dir_object *pdo)
 813 {
 814         struct gss_pipe *gss_pipe = pdo->pdo_data;
 815         struct rpc_pipe *pipe = gss_pipe->pipe;
 816
 817         if (pipe->dentry != NULL) {
 818                 rpc_unlink(pipe->dentry);
 819                 pipe->dentry = NULL;
 820         }
 821 }
 822
 823 static int gss_pipe_dentry_create(struct dentry *dir,
 824                 struct rpc_pipe_dir_object *pdo)
 825 {
 826         struct gss_pipe *p = pdo->pdo_data;
 827         struct dentry *dentry;
 828
 829         dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 830         if (IS_ERR(dentry))
 831                 return PTR_ERR(dentry);
 832         p->pipe->dentry = dentry;
 833         return 0;
 834 }
 835
 836 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 837         .create = gss_pipe_dentry_create,
 838         .destroy = gss_pipe_dentry_destroy,
 839 };
 840
 841 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 842                 const char *name,
 843                 const struct rpc_pipe_ops *upcall_ops)
 844 {
 845         struct gss_pipe *p;
 846         int err = -ENOMEM;
 847
 848         p = kmalloc(sizeof(*p), GFP_KERNEL);
 849         if (p == NULL)
 850                 goto err;
 851         p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 852         if (IS_ERR(p->pipe)) {
 853                 err = PTR_ERR(p->pipe);
 854                 goto err_free_gss_pipe;
 855         }
 856         p->name = name;
 857         p->clnt = clnt;
 858         kref_init(&p->kref);
 859         rpc_init_pipe_dir_object(&p->pdo,
 860                         &gss_pipe_dir_object_ops,
 861                         p);
 862         return p;
 863 err_free_gss_pipe:
 864         kfree(p);
 865 err:
 866         return ERR_PTR(err);
 867 }
 868
 869 struct gss_alloc_pdo {
 870         struct rpc_clnt *clnt;
 871         const char *name;
 872         const struct rpc_pipe_ops *upcall_ops;
 873 };
 874
 875 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 876 {
 877         struct gss_pipe *gss_pipe;
 878         struct gss_alloc_pdo *args = data;
 879
 880         if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 881                 return 0;
 882         gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 883         if (strcmp(gss_pipe->name, args->name) != 0)
 884                 return 0;
 885         if (!kref_get_unless_zero(&gss_pipe->kref))
 886                 return 0;
 887         return 1;
 888 }
 889
 890 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 891 {
 892         struct gss_pipe *gss_pipe;
 893         struct gss_alloc_pdo *args = data;
 894
 895         gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 896         if (!IS_ERR(gss_pipe))
 897                 return &gss_pipe->pdo;
 898         return NULL;
 899 }
 900
 901 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 902                 const char *name,
 903                 const struct rpc_pipe_ops *upcall_ops)
 904 {
 905         struct net *net = rpc_net_ns(clnt);
 906         struct rpc_pipe_dir_object *pdo;
 907         struct gss_alloc_pdo args = {
 908                 .clnt = clnt,
 909                 .name = name,
 910                 .upcall_ops = upcall_ops,
 911         };
 912
 913         pdo = rpc_find_or_alloc_pipe_dir_object(net,
 914                         &clnt->cl_pipedir_objects,
 915                         gss_pipe_match_pdo,
 916                         gss_pipe_alloc_pdo,
 917                         &args);
 918         if (pdo != NULL)
 919                 return container_of(pdo, struct gss_pipe, pdo);
 920         return ERR_PTR(-ENOMEM);
 921 }
 922
 923 static void __gss_pipe_free(struct gss_pipe *p)
 924 {
 925         struct rpc_clnt *clnt = p->clnt;
 926         struct net *net = rpc_net_ns(clnt);
 927
 928         rpc_remove_pipe_dir_object(net,
 929                         &clnt->cl_pipedir_objects,
 930                         &p->pdo);
 931         rpc_destroy_pipe_data(p->pipe);
 932         kfree(p);
 933 }
 934
 935 static void __gss_pipe_release(struct kref *kref)
 936 {
 937         struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
 938
 939         __gss_pipe_free(p);
 940 }
 941
 942 static void gss_pipe_free(struct gss_pipe *p)
 943 {
 944         if (p != NULL)
 945                 kref_put(&p->kref, __gss_pipe_release);
 946 }
 947
 948 /*
 949  * NOTE: we have the opportunity to use different
 950  * parameters based on the input flavor (which must be a pseudoflavor)
 951  */
 952 static struct gss_auth *
 953 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 954 {
 955         rpc_authflavor_t flavor = args->pseudoflavor;
 956         struct gss_auth *gss_auth;
 957         struct gss_pipe *gss_pipe;
 958         struct rpc_auth * auth;
 959         int err = -ENOMEM; /* XXX? */
 960
 961         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 962
 963         if (!try_module_get(THIS_MODULE))
 964                 return ERR_PTR(err);
 965         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 966                 goto out_dec;
 967         INIT_HLIST_NODE(&gss_auth->hash);
 968         gss_auth->target_name = NULL;
 969         if (args->target_name) {
 970                 gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
 971                 if (gss_auth->target_name == NULL)
 972                         goto err_free;
 973         }
 974         gss_auth->client = clnt;
 975         gss_auth->net = get_net(rpc_net_ns(clnt));
 976         err = -EINVAL;
 977         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 978         if (!gss_auth->mech) {
 979                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
 980                 goto err_put_net;
 981         }
 982         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 983         if (gss_auth->service == 0)
 984                 goto err_put_mech;
 985         auth = &gss_auth->rpc_auth;
 986         auth->au_cslack = GSS_CRED_SLACK >> 2;
 987         auth->au_rslack = GSS_VERF_SLACK >> 2;
 988         auth->au_ops = &authgss_ops;
 989         auth->au_flavor = flavor;
 990         atomic_set(&auth->au_count, 1);
 991         kref_init(&gss_auth->kref);
 992
 993         err = rpcauth_init_credcache(auth);
 994         if (err)
 995                 goto err_put_mech;
 996         /*
 997          * Note: if we created the old pipe first, then someone who
 998          * examined the directory at the right moment might conclude
 999          * that we supported only the old pipe.  So we instead create
1000          * the new pipe first.
1001          */
1002         gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1003         if (IS_ERR(gss_pipe)) {
1004                 err = PTR_ERR(gss_pipe);
1005                 goto err_destroy_credcache;
1006         }
1007         gss_auth->gss_pipe[1] = gss_pipe;
1008
1009         gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1010                         &gss_upcall_ops_v0);
1011         if (IS_ERR(gss_pipe)) {
1012                 err = PTR_ERR(gss_pipe);
1013                 goto err_destroy_pipe_1;
1014         }
1015         gss_auth->gss_pipe[0] = gss_pipe;
1016
1017         return gss_auth;
1018 err_destroy_pipe_1:
1019         gss_pipe_free(gss_auth->gss_pipe[1]);
1020 err_destroy_credcache:
1021         rpcauth_destroy_credcache(auth);
1022 err_put_mech:
1023         gss_mech_put(gss_auth->mech);
1024 err_put_net:
1025         put_net(gss_auth->net);
1026 err_free:
1027         kfree(gss_auth->target_name);
1028         kfree(gss_auth);
1029 out_dec:
1030         module_put(THIS_MODULE);
1031         return ERR_PTR(err);
1032 }
1033
1034 static void
1035 gss_free(struct gss_auth *gss_auth)
1036 {
1037         gss_pipe_free(gss_auth->gss_pipe[0]);
1038         gss_pipe_free(gss_auth->gss_pipe[1]);
1039         gss_mech_put(gss_auth->mech);
1040         put_net(gss_auth->net);
1041         kfree(gss_auth->target_name);
1042
1043         kfree(gss_auth);
1044         module_put(THIS_MODULE);
1045 }
1046
1047 static void
1048 gss_free_callback(struct kref *kref)
1049 {
1050         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1051
1052         gss_free(gss_auth);
1053 }
1054
1055 static void
1056 gss_destroy(struct rpc_auth *auth)
1057 {
1058         struct gss_auth *gss_auth = container_of(auth,
1059                         struct gss_auth, rpc_auth);
1060
1061         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1062                         auth, auth->au_flavor);
1063
1064         if (hash_hashed(&gss_auth->hash)) {
1065                 spin_lock(&gss_auth_hash_lock);
1066                 hash_del(&gss_auth->hash);
1067                 spin_unlock(&gss_auth_hash_lock);
1068         }
1069
1070         gss_pipe_free(gss_auth->gss_pipe[0]);
1071         gss_auth->gss_pipe[0] = NULL;
1072         gss_pipe_free(gss_auth->gss_pipe[1]);
1073         gss_auth->gss_pipe[1] = NULL;
1074         rpcauth_destroy_credcache(auth);
1075
1076         kref_put(&gss_auth->kref, gss_free_callback);
1077 }
1078
1079 /*
1080  * Auths may be shared between rpc clients that were cloned from a
1081  * common client with the same xprt, if they also share the flavor and
1082  * target_name.
1083  *
1084  * The auth is looked up from the oldest parent sharing the same
1085  * cl_xprt, and the auth itself references only that common parent
1086  * (which is guaranteed to last as long as any of its descendants).
1087  */
1088 static struct gss_auth *
1089 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1090                 struct rpc_clnt *clnt,
1091                 struct gss_auth *new)
1092 {
1093         struct gss_auth *gss_auth;
1094         unsigned long hashval = (unsigned long)clnt;
1095
1096         spin_lock(&gss_auth_hash_lock);
1097         hash_for_each_possible(gss_auth_hash_table,
1098                         gss_auth,
1099                         hash,
1100                         hashval) {
1101                 if (gss_auth->client != clnt)
1102                         continue;
1103                 if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1104                         continue;
1105                 if (gss_auth->target_name != args->target_name) {
1106                         if (gss_auth->target_name == NULL)
1107                                 continue;
1108                         if (args->target_name == NULL)
1109                                 continue;
1110                         if (strcmp(gss_auth->target_name, args->target_name))
1111                                 continue;
1112                 }
1113                 if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1114                         continue;
1115                 goto out;
1116         }
1117         if (new)
1118                 hash_add(gss_auth_hash_table, &new->hash, hashval);
1119         gss_auth = new;
1120 out:
1121         spin_unlock(&gss_auth_hash_lock);
1122         return gss_auth;
1123 }
1124
1125 static struct gss_auth *
1126 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1127 {
1128         struct gss_auth *gss_auth;
1129         struct gss_auth *new;
1130
1131         gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1132         if (gss_auth != NULL)
1133                 goto out;
1134         new = gss_create_new(args, clnt);
1135         if (IS_ERR(new))
1136                 return new;
1137         gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1138         if (gss_auth != new)
1139                 gss_destroy(&new->rpc_auth);
1140 out:
1141         return gss_auth;
1142 }
1143
1144 static struct rpc_auth *
1145 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1146 {
1147         struct gss_auth *gss_auth;
1148         struct rpc_xprt *xprt = rcu_access_pointer(clnt->cl_xprt);
1149
1150         while (clnt != clnt->cl_parent) {
1151                 struct rpc_clnt *parent = clnt->cl_parent;
1152                 /* Find the original parent for this transport */
1153                 if (rcu_access_pointer(parent->cl_xprt) != xprt)
1154                         break;
1155                 clnt = parent;
1156         }
1157
1158         gss_auth = gss_create_hashed(args, clnt);
1159         if (IS_ERR(gss_auth))
1160                 return ERR_CAST(gss_auth);
1161         return &gss_auth->rpc_auth;
1162 }
1163
1164 /*
1165  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1166  * to the server with the GSS control procedure field set to
1167  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1168  * all RPCSEC_GSS state associated with that context.
1169  */
1170 static int
1171 gss_destroying_context(struct rpc_cred *cred)
1172 {
1173         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1174         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1175         struct rpc_task *task;
1176
1177         if (gss_cred->gc_ctx == NULL ||
1178             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1179                 return 0;
1180
1181         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1182         cred->cr_ops = &gss_nullops;
1183
1184         /* Take a reference to ensure the cred will be destroyed either
1185          * by the RPC call or by the put_rpccred() below */
1186         get_rpccred(cred);
1187
1188         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1189         if (!IS_ERR(task))
1190                 rpc_put_task(task);
1191
1192         put_rpccred(cred);
1193         return 1;
1194 }
1195
1196 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1197  * to create a new cred or context, so they check that things have been
1198  * allocated before freeing them. */
1199 static void
1200 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1201 {
1202         dprintk("RPC:       %s\n", __func__);
1203
1204         gss_delete_sec_context(&ctx->gc_gss_ctx);
1205         kfree(ctx->gc_wire_ctx.data);
1206         kfree(ctx);
1207 }
1208
1209 static void
1210 gss_free_ctx_callback(struct rcu_head *head)
1211 {
1212         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1213         gss_do_free_ctx(ctx);
1214 }
1215
1216 static void
1217 gss_free_ctx(struct gss_cl_ctx *ctx)
1218 {
1219         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1220 }
1221
1222 static void
1223 gss_free_cred(struct gss_cred *gss_cred)
1224 {
1225         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1226         kfree(gss_cred);
1227 }
1228
1229 static void
1230 gss_free_cred_callback(struct rcu_head *head)
1231 {
1232         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1233         gss_free_cred(gss_cred);
1234 }
1235
1236 static void
1237 gss_destroy_nullcred(struct rpc_cred *cred)
1238 {
1239         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1240         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1241         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
1242
1243         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1244         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1245         if (ctx)
1246                 gss_put_ctx(ctx);
1247         kref_put(&gss_auth->kref, gss_free_callback);
1248 }
1249
1250 static void
1251 gss_destroy_cred(struct rpc_cred *cred)
1252 {
1253
1254         if (gss_destroying_context(cred))
1255                 return;
1256         gss_destroy_nullcred(cred);
1257 }
1258
1259 /*
1260  * Lookup RPCSEC_GSS cred for the current process
1261  */
1262 static struct rpc_cred *
1263 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1264 {
1265         return rpcauth_lookup_credcache(auth, acred, flags);
1266 }
1267
1268 static struct rpc_cred *
1269 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1270 {
1271         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1272         struct gss_cred *cred = NULL;
1273         int err = -ENOMEM;
1274
1275         dprintk("RPC:       %s for uid %d, flavor %d\n",
1276                 __func__, from_kuid(&init_user_ns, acred->uid),
1277                 auth->au_flavor);
1278
1279         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1280                 goto out_err;
1281
1282         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1283         /*
1284          * Note: in order to force a call to call_refresh(), we deliberately
1285          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1286          */
1287         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1288         cred->gc_service = gss_auth->service;
1289         cred->gc_principal = NULL;
1290         if (acred->machine_cred)
1291                 cred->gc_principal = acred->principal;
1292         kref_get(&gss_auth->kref);
1293         return &cred->gc_base;
1294
1295 out_err:
1296         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1297         return ERR_PTR(err);
1298 }
1299
1300 static int
1301 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1302 {
1303         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1304         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1305         int err;
1306
1307         do {
1308                 err = gss_create_upcall(gss_auth, gss_cred);
1309         } while (err == -EAGAIN);
1310         return err;
1311 }
1312
1313 /*
1314  * Returns -EACCES if GSS context is NULL or will expire within the
1315  * timeout (miliseconds)
1316  */
1317 static int
1318 gss_key_timeout(struct rpc_cred *rc)
1319 {
1320         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1321         unsigned long now = jiffies;
1322         unsigned long expire;
1323
1324         if (gss_cred->gc_ctx == NULL)
1325                 return -EACCES;
1326
1327         expire = gss_cred->gc_ctx->gc_expiry - (gss_key_expire_timeo * HZ);
1328
1329         if (time_after(now, expire))
1330                 return -EACCES;
1331         return 0;
1332 }
1333
1334 static int
1335 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1336 {
1337         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1338         int ret;
1339
1340         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1341                 goto out;
1342         /* Don't match with creds that have expired. */
1343         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1344                 return 0;
1345         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1346                 return 0;
1347 out:
1348         if (acred->principal != NULL) {
1349                 if (gss_cred->gc_principal == NULL)
1350                         return 0;
1351                 ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1352                 goto check_expire;
1353         }
1354         if (gss_cred->gc_principal != NULL)
1355                 return 0;
1356         ret = uid_eq(rc->cr_uid, acred->uid);
1357
1358 check_expire:
1359         if (ret == 0)
1360                 return ret;
1361
1362         /* Notify acred users of GSS context expiration timeout */
1363         if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1364             (gss_key_timeout(rc) != 0)) {
1365                 /* test will now be done from generic cred */
1366                 test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1367                 /* tell NFS layer that key will expire soon */
1368                 set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1369         }
1370         return ret;
1371 }
1372
1373 /*
1374 * Marshal credentials.
1375 * Maybe we should keep a cached credential for performance reasons.
1376 */
1377 static __be32 *
1378 gss_marshal(struct rpc_task *task, __be32 *p)
1379 {
1380         struct rpc_rqst *req = task->tk_rqstp;
1381         struct rpc_cred *cred = req->rq_cred;
1382         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1383                                                  gc_base);
1384         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1385         __be32          *cred_len;
1386         u32             maj_stat = 0;
1387         struct xdr_netobj mic;
1388         struct kvec     iov;
1389         struct xdr_buf  verf_buf;
1390
1391         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1392
1393         *p++ = htonl(RPC_AUTH_GSS);
1394         cred_len = p++;
1395
1396         spin_lock(&ctx->gc_seq_lock);
1397         req->rq_seqno = ctx->gc_seq++;
1398         spin_unlock(&ctx->gc_seq_lock);
1399
1400         *p++ = htonl((u32) RPC_GSS_VERSION);
1401         *p++ = htonl((u32) ctx->gc_proc);
1402         *p++ = htonl((u32) req->rq_seqno);
1403         *p++ = htonl((u32) gss_cred->gc_service);
1404         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1405         *cred_len = htonl((p - (cred_len + 1)) << 2);
1406
1407         /* We compute the checksum for the verifier over the xdr-encoded bytes
1408          * starting with the xid and ending at the end of the credential: */
1409         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1410                                         req->rq_snd_buf.head[0].iov_base);
1411         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1412         xdr_buf_from_iov(&iov, &verf_buf);
1413
1414         /* set verifier flavor*/
1415         *p++ = htonl(RPC_AUTH_GSS);
1416
1417         mic.data = (u8 *)(p + 1);
1418         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1419         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1420                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1421         } else if (maj_stat != 0) {
1422                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1423                 goto out_put_ctx;
1424         }
1425         p = xdr_encode_opaque(p, NULL, mic.len);
1426         gss_put_ctx(ctx);
1427         return p;
1428 out_put_ctx:
1429         gss_put_ctx(ctx);
1430         return NULL;
1431 }
1432
1433 static int gss_renew_cred(struct rpc_task *task)
1434 {
1435         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1436         struct gss_cred *gss_cred = container_of(oldcred,
1437                                                  struct gss_cred,
1438                                                  gc_base);
1439         struct rpc_auth *auth = oldcred->cr_auth;
1440         struct auth_cred acred = {
1441                 .uid = oldcred->cr_uid,
1442                 .principal = gss_cred->gc_principal,
1443                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1444         };
1445         struct rpc_cred *new;
1446
1447         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1448         if (IS_ERR(new))
1449                 return PTR_ERR(new);
1450         task->tk_rqstp->rq_cred = new;
1451         put_rpccred(oldcred);
1452         return 0;
1453 }
1454
1455 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1456 {
1457         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1458                 unsigned long now = jiffies;
1459                 unsigned long begin, expire;
1460                 struct gss_cred *gss_cred;
1461
1462                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1463                 begin = gss_cred->gc_upcall_timestamp;
1464                 expire = begin + gss_expired_cred_retry_delay * HZ;
1465
1466                 if (time_in_range_open(now, begin, expire))
1467                         return 1;
1468         }
1469         return 0;
1470 }
1471
1472 /*
1473 * Refresh credentials. XXX - finish
1474 */
1475 static int
1476 gss_refresh(struct rpc_task *task)
1477 {
1478         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1479         int ret = 0;
1480
1481         if (gss_cred_is_negative_entry(cred))
1482                 return -EKEYEXPIRED;
1483
1484         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1485                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1486                 ret = gss_renew_cred(task);
1487                 if (ret < 0)
1488                         goto out;
1489                 cred = task->tk_rqstp->rq_cred;
1490         }
1491
1492         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1493                 ret = gss_refresh_upcall(task);
1494 out:
1495         return ret;
1496 }
1497
1498 /* Dummy refresh routine: used only when destroying the context */
1499 static int
1500 gss_refresh_null(struct rpc_task *task)
1501 {
1502         return -EACCES;
1503 }
1504
1505 static __be32 *
1506 gss_validate(struct rpc_task *task, __be32 *p)
1507 {
1508         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1509         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1510         __be32          seq;
1511         struct kvec     iov;
1512         struct xdr_buf  verf_buf;
1513         struct xdr_netobj mic;
1514         u32             flav,len;
1515         u32             maj_stat;
1516         __be32          *ret = ERR_PTR(-EIO);
1517
1518         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1519
1520         flav = ntohl(*p++);
1521         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1522                 goto out_bad;
1523         if (flav != RPC_AUTH_GSS)
1524                 goto out_bad;
1525         seq = htonl(task->tk_rqstp->rq_seqno);
1526         iov.iov_base = &seq;
1527         iov.iov_len = sizeof(seq);
1528         xdr_buf_from_iov(&iov, &verf_buf);
1529         mic.data = (u8 *)p;
1530         mic.len = len;
1531
1532         ret = ERR_PTR(-EACCES);
1533         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1534         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1535                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1536         if (maj_stat) {
1537                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1538                         task->tk_pid, __func__, maj_stat);
1539                 goto out_bad;
1540         }
1541         /* We leave it to unwrap to calculate au_rslack. For now we just
1542          * calculate the length of the verifier: */
1543         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1544         gss_put_ctx(ctx);
1545         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1546                         task->tk_pid, __func__);
1547         return p + XDR_QUADLEN(len);
1548 out_bad:
1549         gss_put_ctx(ctx);
1550         dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1551                 PTR_ERR(ret));
1552         return ret;
1553 }
1554
1555 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1556                                 __be32 *p, void *obj)
1557 {
1558         struct xdr_stream xdr;
1559
1560         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1561         encode(rqstp, &xdr, obj);
1562 }
1563
1564 static inline int
1565 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1566                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1567                    __be32 *p, void *obj)
1568 {
1569         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1570         struct xdr_buf  integ_buf;
1571         __be32          *integ_len = NULL;
1572         struct xdr_netobj mic;
1573         u32             offset;
1574         __be32          *q;
1575         struct kvec     *iov;
1576         u32             maj_stat = 0;
1577         int             status = -EIO;
1578
1579         integ_len = p++;
1580         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1581         *p++ = htonl(rqstp->rq_seqno);
1582
1583         gss_wrap_req_encode(encode, rqstp, p, obj);
1584
1585         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1586                                 offset, snd_buf->len - offset))
1587                 return status;
1588         *integ_len = htonl(integ_buf.len);
1589
1590         /* guess whether we're in the head or the tail: */
1591         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1592                 iov = snd_buf->tail;
1593         else
1594                 iov = snd_buf->head;
1595         p = iov->iov_base + iov->iov_len;
1596         mic.data = (u8 *)(p + 1);
1597
1598         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1599         status = -EIO; /* XXX? */
1600         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1601                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1602         else if (maj_stat)
1603                 return status;
1604         q = xdr_encode_opaque(p, NULL, mic.len);
1605
1606         offset = (u8 *)q - (u8 *)p;
1607         iov->iov_len += offset;
1608         snd_buf->len += offset;
1609         return 0;
1610 }
1611
1612 static void
1613 priv_release_snd_buf(struct rpc_rqst *rqstp)
1614 {
1615         int i;
1616
1617         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1618                 __free_page(rqstp->rq_enc_pages[i]);
1619         kfree(rqstp->rq_enc_pages);
1620 }
1621
1622 static int
1623 alloc_enc_pages(struct rpc_rqst *rqstp)
1624 {
1625         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1626         int first, last, i;
1627
1628         if (snd_buf->page_len == 0) {
1629                 rqstp->rq_enc_pages_num = 0;
1630                 return 0;
1631         }
1632
1633         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1634         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1635         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1636         rqstp->rq_enc_pages
1637                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1638                                 GFP_NOFS);
1639         if (!rqstp->rq_enc_pages)
1640                 goto out;
1641         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1642                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1643                 if (rqstp->rq_enc_pages[i] == NULL)
1644                         goto out_free;
1645         }
1646         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1647         return 0;
1648 out_free:
1649         rqstp->rq_enc_pages_num = i;
1650         priv_release_snd_buf(rqstp);
1651 out:
1652         return -EAGAIN;
1653 }
1654
1655 static inline int
1656 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1657                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1658                   __be32 *p, void *obj)
1659 {
1660         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1661         u32             offset;
1662         u32             maj_stat;
1663         int             status;
1664         __be32          *opaque_len;
1665         struct page     **inpages;
1666         int             first;
1667         int             pad;
1668         struct kvec     *iov;
1669         char            *tmp;
1670
1671         opaque_len = p++;
1672         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1673         *p++ = htonl(rqstp->rq_seqno);
1674
1675         gss_wrap_req_encode(encode, rqstp, p, obj);
1676
1677         status = alloc_enc_pages(rqstp);
1678         if (status)
1679                 return status;
1680         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1681         inpages = snd_buf->pages + first;
1682         snd_buf->pages = rqstp->rq_enc_pages;
1683         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1684         /*
1685          * Give the tail its own page, in case we need extra space in the
1686          * head when wrapping:
1687          *
1688          * call_allocate() allocates twice the slack space required
1689          * by the authentication flavor to rq_callsize.
1690          * For GSS, slack is GSS_CRED_SLACK.
1691          */
1692         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1693                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1694                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1695                 snd_buf->tail[0].iov_base = tmp;
1696         }
1697         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1698         /* slack space should prevent this ever happening: */
1699         BUG_ON(snd_buf->len > snd_buf->buflen);
1700         status = -EIO;
1701         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1702          * done anyway, so it's safe to put the request on the wire: */
1703         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1704                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1705         else if (maj_stat)
1706                 return status;
1707
1708         *opaque_len = htonl(snd_buf->len - offset);
1709         /* guess whether we're in the head or the tail: */
1710         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1711                 iov = snd_buf->tail;
1712         else
1713                 iov = snd_buf->head;
1714         p = iov->iov_base + iov->iov_len;
1715         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1716         memset(p, 0, pad);
1717         iov->iov_len += pad;
1718         snd_buf->len += pad;
1719
1720         return 0;
1721 }
1722
1723 static int
1724 gss_wrap_req(struct rpc_task *task,
1725              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1726 {
1727         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1728         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1729                         gc_base);
1730         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1731         int             status = -EIO;
1732
1733         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1734         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1735                 /* The spec seems a little ambiguous here, but I think that not
1736                  * wrapping context destruction requests makes the most sense.
1737                  */
1738                 gss_wrap_req_encode(encode, rqstp, p, obj);
1739                 status = 0;
1740                 goto out;
1741         }
1742         switch (gss_cred->gc_service) {
1743         case RPC_GSS_SVC_NONE:
1744                 gss_wrap_req_encode(encode, rqstp, p, obj);
1745                 status = 0;
1746                 break;
1747         case RPC_GSS_SVC_INTEGRITY:
1748                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1749                 break;
1750         case RPC_GSS_SVC_PRIVACY:
1751                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1752                 break;
1753         }
1754 out:
1755         gss_put_ctx(ctx);
1756         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1757         return status;
1758 }
1759
1760 static inline int
1761 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1762                 struct rpc_rqst *rqstp, __be32 **p)
1763 {
1764         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1765         struct xdr_buf integ_buf;
1766         struct xdr_netobj mic;
1767         u32 data_offset, mic_offset;
1768         u32 integ_len;
1769         u32 maj_stat;
1770         int status = -EIO;
1771
1772         integ_len = ntohl(*(*p)++);
1773         if (integ_len & 3)
1774                 return status;
1775         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1776         mic_offset = integ_len + data_offset;
1777         if (mic_offset > rcv_buf->len)
1778                 return status;
1779         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1780                 return status;
1781
1782         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1783                                 mic_offset - data_offset))
1784                 return status;
1785
1786         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1787                 return status;
1788
1789         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1790         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1791                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1792         if (maj_stat != GSS_S_COMPLETE)
1793                 return status;
1794         return 0;
1795 }
1796
1797 static inline int
1798 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1799                 struct rpc_rqst *rqstp, __be32 **p)
1800 {
1801         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1802         u32 offset;
1803         u32 opaque_len;
1804         u32 maj_stat;
1805         int status = -EIO;
1806
1807         opaque_len = ntohl(*(*p)++);
1808         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1809         if (offset + opaque_len > rcv_buf->len)
1810                 return status;
1811         /* remove padding: */
1812         rcv_buf->len = offset + opaque_len;
1813
1814         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1815         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1816                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1817         if (maj_stat != GSS_S_COMPLETE)
1818                 return status;
1819         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1820                 return status;
1821
1822         return 0;
1823 }
1824
1825 static int
1826 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1827                       __be32 *p, void *obj)
1828 {
1829         struct xdr_stream xdr;
1830
1831         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1832         return decode(rqstp, &xdr, obj);
1833 }
1834
1835 static int
1836 gss_unwrap_resp(struct rpc_task *task,
1837                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1838 {
1839         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1840         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1841                         gc_base);
1842         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1843         __be32          *savedp = p;
1844         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1845         int             savedlen = head->iov_len;
1846         int             status = -EIO;
1847
1848         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1849                 goto out_decode;
1850         switch (gss_cred->gc_service) {
1851         case RPC_GSS_SVC_NONE:
1852                 break;
1853         case RPC_GSS_SVC_INTEGRITY:
1854                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1855                 if (status)
1856                         goto out;
1857                 break;
1858         case RPC_GSS_SVC_PRIVACY:
1859                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1860                 if (status)
1861                         goto out;
1862                 break;
1863         }
1864         /* take into account extra slack for integrity and privacy cases: */
1865         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1866                                                 + (savedlen - head->iov_len);
1867 out_decode:
1868         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1869 out:
1870         gss_put_ctx(ctx);
1871         dprintk("RPC: %5u %s returning %d\n",
1872                 task->tk_pid, __func__, status);
1873         return status;
1874 }
1875
1876 static const struct rpc_authops authgss_ops = {
1877         .owner          = THIS_MODULE,
1878         .au_flavor      = RPC_AUTH_GSS,
1879         .au_name        = "RPCSEC_GSS",
1880         .create         = gss_create,
1881         .destroy        = gss_destroy,
1882         .lookup_cred    = gss_lookup_cred,
1883         .crcreate       = gss_create_cred,
1884         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1885         .info2flavor    = gss_mech_info2flavor,
1886         .flavor2info    = gss_mech_flavor2info,
1887 };
1888
1889 static const struct rpc_credops gss_credops = {
1890         .cr_name        = "AUTH_GSS",
1891         .crdestroy      = gss_destroy_cred,
1892         .cr_init        = gss_cred_init,
1893         .crbind         = rpcauth_generic_bind_cred,
1894         .crmatch        = gss_match,
1895         .crmarshal      = gss_marshal,
1896         .crrefresh      = gss_refresh,
1897         .crvalidate     = gss_validate,
1898         .crwrap_req     = gss_wrap_req,
1899         .crunwrap_resp  = gss_unwrap_resp,
1900         .crkey_timeout  = gss_key_timeout,
1901 };
1902
1903 static const struct rpc_credops gss_nullops = {
1904         .cr_name        = "AUTH_GSS",
1905         .crdestroy      = gss_destroy_nullcred,
1906         .crbind         = rpcauth_generic_bind_cred,
1907         .crmatch        = gss_match,
1908         .crmarshal      = gss_marshal,
1909         .crrefresh      = gss_refresh_null,
1910         .crvalidate     = gss_validate,
1911         .crwrap_req     = gss_wrap_req,
1912         .crunwrap_resp  = gss_unwrap_resp,
1913 };
1914
1915 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1916         .upcall         = rpc_pipe_generic_upcall,
1917         .downcall       = gss_pipe_downcall,
1918         .destroy_msg    = gss_pipe_destroy_msg,
1919         .open_pipe      = gss_pipe_open_v0,
1920         .release_pipe   = gss_pipe_release,
1921 };
1922
1923 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1924         .upcall         = rpc_pipe_generic_upcall,
1925         .downcall       = gss_pipe_downcall,
1926         .destroy_msg    = gss_pipe_destroy_msg,
1927         .open_pipe      = gss_pipe_open_v1,
1928         .release_pipe   = gss_pipe_release,
1929 };
1930
1931 static __net_init int rpcsec_gss_init_net(struct net *net)
1932 {
1933         return gss_svc_init_net(net);
1934 }
1935
1936 static __net_exit void rpcsec_gss_exit_net(struct net *net)
1937 {
1938         gss_svc_shutdown_net(net);
1939 }
1940
1941 static struct pernet_operations rpcsec_gss_net_ops = {
1942         .init = rpcsec_gss_init_net,
1943         .exit = rpcsec_gss_exit_net,
1944 };
1945
1946 /*
1947  * Initialize RPCSEC_GSS module
1948  */
1949 static int __init init_rpcsec_gss(void)
1950 {
1951         int err = 0;
1952
1953         err = rpcauth_register(&authgss_ops);
1954         if (err)
1955                 goto out;
1956         err = gss_svc_init();
1957         if (err)
1958                 goto out_unregister;
1959         err = register_pernet_subsys(&rpcsec_gss_net_ops);
1960         if (err)
1961                 goto out_svc_exit;
1962         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1963         return 0;
1964 out_svc_exit:
1965         gss_svc_shutdown();
1966 out_unregister:
1967         rpcauth_unregister(&authgss_ops);
1968 out:
1969         return err;
1970 }
1971
1972 static void __exit exit_rpcsec_gss(void)
1973 {
1974         unregister_pernet_subsys(&rpcsec_gss_net_ops);
1975         gss_svc_shutdown();
1976         rpcauth_unregister(&authgss_ops);
1977         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1978 }
1979
1980 MODULE_ALIAS("rpc-auth-6");
1981 MODULE_LICENSE("GPL");
1982 module_param_named(expired_cred_retry_delay,
1983                    gss_expired_cred_retry_delay,
1984                    uint, 0644);
1985 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
1986                 "the RPC engine retries an expired credential");
1987
1988 module_param_named(key_expire_timeo,
1989                    gss_key_expire_timeo,
1990                    uint, 0644);
1991 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
1992                 "credential keys lifetime where the NFS layer cleans up "
1993                 "prior to key expiration");
1994
1995 module_init(init_rpcsec_gss)
1996 module_exit(exit_rpcsec_gss)