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
  55 static const struct rpc_authops authgss_ops;
  56
  57 static const struct rpc_credops gss_credops;
  58 static const struct rpc_credops gss_nullops;
  59
  60 #define GSS_RETRY_EXPIRED 5
  61 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  62
  63 #ifdef RPC_DEBUG
  64 # define RPCDBG_FACILITY        RPCDBG_AUTH
  65 #endif
  66
  67 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  68 /* length of a krb5 verifier (48), plus data added before arguments when
  69  * using integrity (two 4-byte integers): */
  70 #define GSS_VERF_SLACK          100
  71
  72 struct gss_auth {
  73         struct kref kref;
  74         struct rpc_auth rpc_auth;
  75         struct gss_api_mech *mech;
  76         enum rpc_gss_svc service;
  77         struct rpc_clnt *client;
  78         /*
  79          * There are two upcall pipes; dentry[1], named "gssd", is used
  80          * for the new text-based upcall; dentry[0] is named after the
  81          * mechanism (for example, "krb5") and exists for
  82          * backwards-compatibility with older gssd's.
  83          */
  84         struct dentry *dentry[2];
  85 };
  86
  87 /* pipe_version >= 0 if and only if someone has a pipe open. */
  88 static int pipe_version = -1;
  89 static atomic_t pipe_users = ATOMIC_INIT(0);
  90 static DEFINE_SPINLOCK(pipe_version_lock);
  91 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
  92 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
  93
  94 static void gss_free_ctx(struct gss_cl_ctx *);
  95 static const struct rpc_pipe_ops gss_upcall_ops_v0;
  96 static const struct rpc_pipe_ops gss_upcall_ops_v1;
  97
  98 static inline struct gss_cl_ctx *
  99 gss_get_ctx(struct gss_cl_ctx *ctx)
 100 {
 101         atomic_inc(&ctx->count);
 102         return ctx;
 103 }
 104
 105 static inline void
 106 gss_put_ctx(struct gss_cl_ctx *ctx)
 107 {
 108         if (atomic_dec_and_test(&ctx->count))
 109                 gss_free_ctx(ctx);
 110 }
 111
 112 /* gss_cred_set_ctx:
 113  * called by gss_upcall_callback and gss_create_upcall in order
 114  * to set the gss context. The actual exchange of an old context
 115  * and a new one is protected by the inode->i_lock.
 116  */
 117 static void
 118 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 119 {
 120         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 121
 122         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 123                 return;
 124         gss_get_ctx(ctx);
 125         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 126         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 127         smp_mb__before_clear_bit();
 128         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 129 }
 130
 131 static const void *
 132 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 133 {
 134         const void *q = (const void *)((const char *)p + len);
 135         if (unlikely(q > end || q < p))
 136                 return ERR_PTR(-EFAULT);
 137         memcpy(res, p, len);
 138         return q;
 139 }
 140
 141 static inline const void *
 142 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 143 {
 144         const void *q;
 145         unsigned int len;
 146
 147         p = simple_get_bytes(p, end, &len, sizeof(len));
 148         if (IS_ERR(p))
 149                 return p;
 150         q = (const void *)((const char *)p + len);
 151         if (unlikely(q > end || q < p))
 152                 return ERR_PTR(-EFAULT);
 153         dest->data = kmemdup(p, len, GFP_NOFS);
 154         if (unlikely(dest->data == NULL))
 155                 return ERR_PTR(-ENOMEM);
 156         dest->len = len;
 157         return q;
 158 }
 159
 160 static struct gss_cl_ctx *
 161 gss_cred_get_ctx(struct rpc_cred *cred)
 162 {
 163         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 164         struct gss_cl_ctx *ctx = NULL;
 165
 166         rcu_read_lock();
 167         if (gss_cred->gc_ctx)
 168                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 169         rcu_read_unlock();
 170         return ctx;
 171 }
 172
 173 static struct gss_cl_ctx *
 174 gss_alloc_context(void)
 175 {
 176         struct gss_cl_ctx *ctx;
 177
 178         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 179         if (ctx != NULL) {
 180                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 181                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 182                 spin_lock_init(&ctx->gc_seq_lock);
 183                 atomic_set(&ctx->count,1);
 184         }
 185         return ctx;
 186 }
 187
 188 #define GSSD_MIN_TIMEOUT (60 * 60)
 189 static const void *
 190 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 191 {
 192         const void *q;
 193         unsigned int seclen;
 194         unsigned int timeout;
 195         u32 window_size;
 196         int ret;
 197
 198         /* First unsigned int gives the lifetime (in seconds) of the cred */
 199         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 200         if (IS_ERR(p))
 201                 goto err;
 202         if (timeout == 0)
 203                 timeout = GSSD_MIN_TIMEOUT;
 204         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 205         /* Sequence number window. Determines the maximum number of simultaneous requests */
 206         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 207         if (IS_ERR(p))
 208                 goto err;
 209         ctx->gc_win = window_size;
 210         /* gssd signals an error by passing ctx->gc_win = 0: */
 211         if (ctx->gc_win == 0) {
 212                 /*
 213                  * in which case, p points to an error code. Anything other
 214                  * than -EKEYEXPIRED gets converted to -EACCES.
 215                  */
 216                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 217                 if (!IS_ERR(p))
 218                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 219                                                     ERR_PTR(-EACCES);
 220                 goto err;
 221         }
 222         /* copy the opaque wire context */
 223         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 224         if (IS_ERR(p))
 225                 goto err;
 226         /* import the opaque security context */
 227         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 228         if (IS_ERR(p))
 229                 goto err;
 230         q = (const void *)((const char *)p + seclen);
 231         if (unlikely(q > end || q < p)) {
 232                 p = ERR_PTR(-EFAULT);
 233                 goto err;
 234         }
 235         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, GFP_NOFS);
 236         if (ret < 0) {
 237                 p = ERR_PTR(ret);
 238                 goto err;
 239         }
 240         return q;
 241 err:
 242         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 243         return p;
 244 }
 245
 246 #define UPCALL_BUF_LEN 128
 247
 248 struct gss_upcall_msg {
 249         atomic_t count;
 250         uid_t   uid;
 251         struct rpc_pipe_msg msg;
 252         struct list_head list;
 253         struct gss_auth *auth;
 254         struct rpc_inode *inode;
 255         struct rpc_wait_queue rpc_waitqueue;
 256         wait_queue_head_t waitqueue;
 257         struct gss_cl_ctx *ctx;
 258         char databuf[UPCALL_BUF_LEN];
 259 };
 260
 261 static int get_pipe_version(void)
 262 {
 263         int ret;
 264
 265         spin_lock(&pipe_version_lock);
 266         if (pipe_version >= 0) {
 267                 atomic_inc(&pipe_users);
 268                 ret = pipe_version;
 269         } else
 270                 ret = -EAGAIN;
 271         spin_unlock(&pipe_version_lock);
 272         return ret;
 273 }
 274
 275 static void put_pipe_version(void)
 276 {
 277         if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
 278                 pipe_version = -1;
 279                 spin_unlock(&pipe_version_lock);
 280         }
 281 }
 282
 283 static void
 284 gss_release_msg(struct gss_upcall_msg *gss_msg)
 285 {
 286         if (!atomic_dec_and_test(&gss_msg->count))
 287                 return;
 288         put_pipe_version();
 289         BUG_ON(!list_empty(&gss_msg->list));
 290         if (gss_msg->ctx != NULL)
 291                 gss_put_ctx(gss_msg->ctx);
 292         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 293         kfree(gss_msg);
 294 }
 295
 296 static struct gss_upcall_msg *
 297 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 298 {
 299         struct gss_upcall_msg *pos;
 300         list_for_each_entry(pos, &rpci->in_downcall, list) {
 301                 if (pos->uid != uid)
 302                         continue;
 303                 atomic_inc(&pos->count);
 304                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 305                 return pos;
 306         }
 307         dprintk("RPC:       gss_find_upcall found nothing\n");
 308         return NULL;
 309 }
 310
 311 /* Try to add an upcall to the pipefs queue.
 312  * If an upcall owned by our uid already exists, then we return a reference
 313  * to that upcall instead of adding the new upcall.
 314  */
 315 static inline struct gss_upcall_msg *
 316 gss_add_msg(struct gss_upcall_msg *gss_msg)
 317 {
 318         struct rpc_inode *rpci = gss_msg->inode;
 319         struct inode *inode = &rpci->vfs_inode;
 320         struct gss_upcall_msg *old;
 321
 322         spin_lock(&inode->i_lock);
 323         old = __gss_find_upcall(rpci, gss_msg->uid);
 324         if (old == NULL) {
 325                 atomic_inc(&gss_msg->count);
 326                 list_add(&gss_msg->list, &rpci->in_downcall);
 327         } else
 328                 gss_msg = old;
 329         spin_unlock(&inode->i_lock);
 330         return gss_msg;
 331 }
 332
 333 static void
 334 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 335 {
 336         list_del_init(&gss_msg->list);
 337         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 338         wake_up_all(&gss_msg->waitqueue);
 339         atomic_dec(&gss_msg->count);
 340 }
 341
 342 static void
 343 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 344 {
 345         struct inode *inode = &gss_msg->inode->vfs_inode;
 346
 347         if (list_empty(&gss_msg->list))
 348                 return;
 349         spin_lock(&inode->i_lock);
 350         if (!list_empty(&gss_msg->list))
 351                 __gss_unhash_msg(gss_msg);
 352         spin_unlock(&inode->i_lock);
 353 }
 354
 355 static void
 356 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 357 {
 358         switch (gss_msg->msg.errno) {
 359         case 0:
 360                 if (gss_msg->ctx == NULL)
 361                         break;
 362                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 363                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 364                 break;
 365         case -EKEYEXPIRED:
 366                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 367         }
 368         gss_cred->gc_upcall_timestamp = jiffies;
 369         gss_cred->gc_upcall = NULL;
 370         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 371 }
 372
 373 static void
 374 gss_upcall_callback(struct rpc_task *task)
 375 {
 376         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 377                         struct gss_cred, gc_base);
 378         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 379         struct inode *inode = &gss_msg->inode->vfs_inode;
 380
 381         spin_lock(&inode->i_lock);
 382         gss_handle_downcall_result(gss_cred, gss_msg);
 383         spin_unlock(&inode->i_lock);
 384         task->tk_status = gss_msg->msg.errno;
 385         gss_release_msg(gss_msg);
 386 }
 387
 388 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 389 {
 390         gss_msg->msg.data = &gss_msg->uid;
 391         gss_msg->msg.len = sizeof(gss_msg->uid);
 392 }
 393
 394 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 395                                 struct rpc_clnt *clnt, int machine_cred)
 396 {
 397         struct gss_api_mech *mech = gss_msg->auth->mech;
 398         char *p = gss_msg->databuf;
 399         int len = 0;
 400
 401         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
 402                                    mech->gm_name,
 403                                    gss_msg->uid);
 404         p += gss_msg->msg.len;
 405         if (clnt->cl_principal) {
 406                 len = sprintf(p, "target=%s ", clnt->cl_principal);
 407                 p += len;
 408                 gss_msg->msg.len += len;
 409         }
 410         if (machine_cred) {
 411                 len = sprintf(p, "service=* ");
 412                 p += len;
 413                 gss_msg->msg.len += len;
 414         } else if (!strcmp(clnt->cl_program->name, "nfs4_cb")) {
 415                 len = sprintf(p, "service=nfs ");
 416                 p += len;
 417                 gss_msg->msg.len += len;
 418         }
 419         if (mech->gm_upcall_enctypes) {
 420                 len = sprintf(p, "enctypes=%s ", mech->gm_upcall_enctypes);
 421                 p += len;
 422                 gss_msg->msg.len += len;
 423         }
 424         len = sprintf(p, "\n");
 425         gss_msg->msg.len += len;
 426
 427         gss_msg->msg.data = gss_msg->databuf;
 428         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
 429 }
 430
 431 static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
 432                                 struct rpc_clnt *clnt, int machine_cred)
 433 {
 434         if (pipe_version == 0)
 435                 gss_encode_v0_msg(gss_msg);
 436         else /* pipe_version == 1 */
 437                 gss_encode_v1_msg(gss_msg, clnt, machine_cred);
 438 }
 439
 440 static inline struct gss_upcall_msg *
 441 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid, struct rpc_clnt *clnt,
 442                 int machine_cred)
 443 {
 444         struct gss_upcall_msg *gss_msg;
 445         int vers;
 446
 447         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 448         if (gss_msg == NULL)
 449                 return ERR_PTR(-ENOMEM);
 450         vers = get_pipe_version();
 451         if (vers < 0) {
 452                 kfree(gss_msg);
 453                 return ERR_PTR(vers);
 454         }
 455         gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode);
 456         INIT_LIST_HEAD(&gss_msg->list);
 457         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 458         init_waitqueue_head(&gss_msg->waitqueue);
 459         atomic_set(&gss_msg->count, 1);
 460         gss_msg->uid = uid;
 461         gss_msg->auth = gss_auth;
 462         gss_encode_msg(gss_msg, clnt, machine_cred);
 463         return gss_msg;
 464 }
 465
 466 static struct gss_upcall_msg *
 467 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 468 {
 469         struct gss_cred *gss_cred = container_of(cred,
 470                         struct gss_cred, gc_base);
 471         struct gss_upcall_msg *gss_new, *gss_msg;
 472         uid_t uid = cred->cr_uid;
 473
 474         gss_new = gss_alloc_msg(gss_auth, uid, clnt, gss_cred->gc_machine_cred);
 475         if (IS_ERR(gss_new))
 476                 return gss_new;
 477         gss_msg = gss_add_msg(gss_new);
 478         if (gss_msg == gss_new) {
 479                 struct inode *inode = &gss_new->inode->vfs_inode;
 480                 int res = rpc_queue_upcall(inode, &gss_new->msg);
 481                 if (res) {
 482                         gss_unhash_msg(gss_new);
 483                         gss_msg = ERR_PTR(res);
 484                 }
 485         } else
 486                 gss_release_msg(gss_new);
 487         return gss_msg;
 488 }
 489
 490 static void warn_gssd(void)
 491 {
 492         static unsigned long ratelimit;
 493         unsigned long now = jiffies;
 494
 495         if (time_after(now, ratelimit)) {
 496                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 497                                 "Please check user daemon is running.\n");
 498                 ratelimit = now + 15*HZ;
 499         }
 500 }
 501
 502 static inline int
 503 gss_refresh_upcall(struct rpc_task *task)
 504 {
 505         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 506         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 507                         struct gss_auth, rpc_auth);
 508         struct gss_cred *gss_cred = container_of(cred,
 509                         struct gss_cred, gc_base);
 510         struct gss_upcall_msg *gss_msg;
 511         struct inode *inode;
 512         int err = 0;
 513
 514         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 515                                                                 cred->cr_uid);
 516         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 517         if (PTR_ERR(gss_msg) == -EAGAIN) {
 518                 /* XXX: warning on the first, under the assumption we
 519                  * shouldn't normally hit this case on a refresh. */
 520                 warn_gssd();
 521                 task->tk_timeout = 15*HZ;
 522                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 523                 return -EAGAIN;
 524         }
 525         if (IS_ERR(gss_msg)) {
 526                 err = PTR_ERR(gss_msg);
 527                 goto out;
 528         }
 529         inode = &gss_msg->inode->vfs_inode;
 530         spin_lock(&inode->i_lock);
 531         if (gss_cred->gc_upcall != NULL)
 532                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 533         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 534                 task->tk_timeout = 0;
 535                 gss_cred->gc_upcall = gss_msg;
 536                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 537                 atomic_inc(&gss_msg->count);
 538                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 539         } else {
 540                 gss_handle_downcall_result(gss_cred, gss_msg);
 541                 err = gss_msg->msg.errno;
 542         }
 543         spin_unlock(&inode->i_lock);
 544         gss_release_msg(gss_msg);
 545 out:
 546         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 547                         task->tk_pid, cred->cr_uid, err);
 548         return err;
 549 }
 550
 551 static inline int
 552 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 553 {
 554         struct inode *inode;
 555         struct rpc_cred *cred = &gss_cred->gc_base;
 556         struct gss_upcall_msg *gss_msg;
 557         DEFINE_WAIT(wait);
 558         int err = 0;
 559
 560         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 561 retry:
 562         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 563         if (PTR_ERR(gss_msg) == -EAGAIN) {
 564                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 565                                 pipe_version >= 0, 15*HZ);
 566                 if (pipe_version < 0) {
 567                         warn_gssd();
 568                         err = -EACCES;
 569                 }
 570                 if (err)
 571                         goto out;
 572                 goto retry;
 573         }
 574         if (IS_ERR(gss_msg)) {
 575                 err = PTR_ERR(gss_msg);
 576                 goto out;
 577         }
 578         inode = &gss_msg->inode->vfs_inode;
 579         for (;;) {
 580                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 581                 spin_lock(&inode->i_lock);
 582                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 583                         break;
 584                 }
 585                 spin_unlock(&inode->i_lock);
 586                 if (fatal_signal_pending(current)) {
 587                         err = -ERESTARTSYS;
 588                         goto out_intr;
 589                 }
 590                 schedule();
 591         }
 592         if (gss_msg->ctx)
 593                 gss_cred_set_ctx(cred, gss_msg->ctx);
 594         else
 595                 err = gss_msg->msg.errno;
 596         spin_unlock(&inode->i_lock);
 597 out_intr:
 598         finish_wait(&gss_msg->waitqueue, &wait);
 599         gss_release_msg(gss_msg);
 600 out:
 601         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 602                         cred->cr_uid, err);
 603         return err;
 604 }
 605
 606 static ssize_t
 607 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 608                 char __user *dst, size_t buflen)
 609 {
 610         char *data = (char *)msg->data + msg->copied;
 611         size_t mlen = min(msg->len, buflen);
 612         unsigned long left;
 613
 614         left = copy_to_user(dst, data, mlen);
 615         if (left == mlen) {
 616                 msg->errno = -EFAULT;
 617                 return -EFAULT;
 618         }
 619
 620         mlen -= left;
 621         msg->copied += mlen;
 622         msg->errno = 0;
 623         return mlen;
 624 }
 625
 626 #define MSG_BUF_MAXSIZE 1024
 627
 628 static ssize_t
 629 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 630 {
 631         const void *p, *end;
 632         void *buf;
 633         struct gss_upcall_msg *gss_msg;
 634         struct inode *inode = filp->f_path.dentry->d_inode;
 635         struct gss_cl_ctx *ctx;
 636         uid_t uid;
 637         ssize_t err = -EFBIG;
 638
 639         if (mlen > MSG_BUF_MAXSIZE)
 640                 goto out;
 641         err = -ENOMEM;
 642         buf = kmalloc(mlen, GFP_NOFS);
 643         if (!buf)
 644                 goto out;
 645
 646         err = -EFAULT;
 647         if (copy_from_user(buf, src, mlen))
 648                 goto err;
 649
 650         end = (const void *)((char *)buf + mlen);
 651         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 652         if (IS_ERR(p)) {
 653                 err = PTR_ERR(p);
 654                 goto err;
 655         }
 656
 657         err = -ENOMEM;
 658         ctx = gss_alloc_context();
 659         if (ctx == NULL)
 660                 goto err;
 661
 662         err = -ENOENT;
 663         /* Find a matching upcall */
 664         spin_lock(&inode->i_lock);
 665         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 666         if (gss_msg == NULL) {
 667                 spin_unlock(&inode->i_lock);
 668                 goto err_put_ctx;
 669         }
 670         list_del_init(&gss_msg->list);
 671         spin_unlock(&inode->i_lock);
 672
 673         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 674         if (IS_ERR(p)) {
 675                 err = PTR_ERR(p);
 676                 switch (err) {
 677                 case -EACCES:
 678                 case -EKEYEXPIRED:
 679                         gss_msg->msg.errno = err;
 680                         err = mlen;
 681                         break;
 682                 case -EFAULT:
 683                 case -ENOMEM:
 684                 case -EINVAL:
 685                 case -ENOSYS:
 686                         gss_msg->msg.errno = -EAGAIN;
 687                         break;
 688                 default:
 689                         printk(KERN_CRIT "%s: bad return from "
 690                                 "gss_fill_context: %zd\n", __func__, err);
 691                         BUG();
 692                 }
 693                 goto err_release_msg;
 694         }
 695         gss_msg->ctx = gss_get_ctx(ctx);
 696         err = mlen;
 697
 698 err_release_msg:
 699         spin_lock(&inode->i_lock);
 700         __gss_unhash_msg(gss_msg);
 701         spin_unlock(&inode->i_lock);
 702         gss_release_msg(gss_msg);
 703 err_put_ctx:
 704         gss_put_ctx(ctx);
 705 err:
 706         kfree(buf);
 707 out:
 708         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 709         return err;
 710 }
 711
 712 static int gss_pipe_open(struct inode *inode, int new_version)
 713 {
 714         int ret = 0;
 715
 716         spin_lock(&pipe_version_lock);
 717         if (pipe_version < 0) {
 718                 /* First open of any gss pipe determines the version: */
 719                 pipe_version = new_version;
 720                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 721                 wake_up(&pipe_version_waitqueue);
 722         } else if (pipe_version != new_version) {
 723                 /* Trying to open a pipe of a different version */
 724                 ret = -EBUSY;
 725                 goto out;
 726         }
 727         atomic_inc(&pipe_users);
 728 out:
 729         spin_unlock(&pipe_version_lock);
 730         return ret;
 731
 732 }
 733
 734 static int gss_pipe_open_v0(struct inode *inode)
 735 {
 736         return gss_pipe_open(inode, 0);
 737 }
 738
 739 static int gss_pipe_open_v1(struct inode *inode)
 740 {
 741         return gss_pipe_open(inode, 1);
 742 }
 743
 744 static void
 745 gss_pipe_release(struct inode *inode)
 746 {
 747         struct rpc_inode *rpci = RPC_I(inode);
 748         struct gss_upcall_msg *gss_msg;
 749
 750 restart:
 751         spin_lock(&inode->i_lock);
 752         list_for_each_entry(gss_msg, &rpci->in_downcall, list) {
 753
 754                 if (!list_empty(&gss_msg->msg.list))
 755                         continue;
 756                 gss_msg->msg.errno = -EPIPE;
 757                 atomic_inc(&gss_msg->count);
 758                 __gss_unhash_msg(gss_msg);
 759                 spin_unlock(&inode->i_lock);
 760                 gss_release_msg(gss_msg);
 761                 goto restart;
 762         }
 763         spin_unlock(&inode->i_lock);
 764
 765         put_pipe_version();
 766 }
 767
 768 static void
 769 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 770 {
 771         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 772
 773         if (msg->errno < 0) {
 774                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 775                                 gss_msg);
 776                 atomic_inc(&gss_msg->count);
 777                 gss_unhash_msg(gss_msg);
 778                 if (msg->errno == -ETIMEDOUT)
 779                         warn_gssd();
 780                 gss_release_msg(gss_msg);
 781         }
 782 }
 783
 784 /*
 785  * NOTE: we have the opportunity to use different
 786  * parameters based on the input flavor (which must be a pseudoflavor)
 787  */
 788 static struct rpc_auth *
 789 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 790 {
 791         struct gss_auth *gss_auth;
 792         struct rpc_auth * auth;
 793         int err = -ENOMEM; /* XXX? */
 794
 795         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 796
 797         if (!try_module_get(THIS_MODULE))
 798                 return ERR_PTR(err);
 799         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 800                 goto out_dec;
 801         gss_auth->client = clnt;
 802         err = -EINVAL;
 803         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 804         if (!gss_auth->mech) {
 805                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 806                                 __func__, flavor);
 807                 goto err_free;
 808         }
 809         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 810         if (gss_auth->service == 0)
 811                 goto err_put_mech;
 812         auth = &gss_auth->rpc_auth;
 813         auth->au_cslack = GSS_CRED_SLACK >> 2;
 814         auth->au_rslack = GSS_VERF_SLACK >> 2;
 815         auth->au_ops = &authgss_ops;
 816         auth->au_flavor = flavor;
 817         atomic_set(&auth->au_count, 1);
 818         kref_init(&gss_auth->kref);
 819
 820         /*
 821          * Note: if we created the old pipe first, then someone who
 822          * examined the directory at the right moment might conclude
 823          * that we supported only the old pipe.  So we instead create
 824          * the new pipe first.
 825          */
 826         gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry,
 827                                          "gssd",
 828                                          clnt, &gss_upcall_ops_v1,
 829                                          RPC_PIPE_WAIT_FOR_OPEN);
 830         if (IS_ERR(gss_auth->dentry[1])) {
 831                 err = PTR_ERR(gss_auth->dentry[1]);
 832                 goto err_put_mech;
 833         }
 834
 835         gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry,
 836                                          gss_auth->mech->gm_name,
 837                                          clnt, &gss_upcall_ops_v0,
 838                                          RPC_PIPE_WAIT_FOR_OPEN);
 839         if (IS_ERR(gss_auth->dentry[0])) {
 840                 err = PTR_ERR(gss_auth->dentry[0]);
 841                 goto err_unlink_pipe_1;
 842         }
 843         err = rpcauth_init_credcache(auth);
 844         if (err)
 845                 goto err_unlink_pipe_0;
 846
 847         return auth;
 848 err_unlink_pipe_0:
 849         rpc_unlink(gss_auth->dentry[0]);
 850 err_unlink_pipe_1:
 851         rpc_unlink(gss_auth->dentry[1]);
 852 err_put_mech:
 853         gss_mech_put(gss_auth->mech);
 854 err_free:
 855         kfree(gss_auth);
 856 out_dec:
 857         module_put(THIS_MODULE);
 858         return ERR_PTR(err);
 859 }
 860
 861 static void
 862 gss_free(struct gss_auth *gss_auth)
 863 {
 864         rpc_unlink(gss_auth->dentry[1]);
 865         rpc_unlink(gss_auth->dentry[0]);
 866         gss_mech_put(gss_auth->mech);
 867
 868         kfree(gss_auth);
 869         module_put(THIS_MODULE);
 870 }
 871
 872 static void
 873 gss_free_callback(struct kref *kref)
 874 {
 875         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 876
 877         gss_free(gss_auth);
 878 }
 879
 880 static void
 881 gss_destroy(struct rpc_auth *auth)
 882 {
 883         struct gss_auth *gss_auth;
 884
 885         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 886                         auth, auth->au_flavor);
 887
 888         rpcauth_destroy_credcache(auth);
 889
 890         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 891         kref_put(&gss_auth->kref, gss_free_callback);
 892 }
 893
 894 /*
 895  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 896  * to the server with the GSS control procedure field set to
 897  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 898  * all RPCSEC_GSS state associated with that context.
 899  */
 900 static int
 901 gss_destroying_context(struct rpc_cred *cred)
 902 {
 903         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 904         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 905         struct rpc_task *task;
 906
 907         if (gss_cred->gc_ctx == NULL ||
 908             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 909                 return 0;
 910
 911         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 912         cred->cr_ops = &gss_nullops;
 913
 914         /* Take a reference to ensure the cred will be destroyed either
 915          * by the RPC call or by the put_rpccred() below */
 916         get_rpccred(cred);
 917
 918         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 919         if (!IS_ERR(task))
 920                 rpc_put_task(task);
 921
 922         put_rpccred(cred);
 923         return 1;
 924 }
 925
 926 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 927  * to create a new cred or context, so they check that things have been
 928  * allocated before freeing them. */
 929 static void
 930 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 931 {
 932         dprintk("RPC:       gss_free_ctx\n");
 933
 934         gss_delete_sec_context(&ctx->gc_gss_ctx);
 935         kfree(ctx->gc_wire_ctx.data);
 936         kfree(ctx);
 937 }
 938
 939 static void
 940 gss_free_ctx_callback(struct rcu_head *head)
 941 {
 942         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 943         gss_do_free_ctx(ctx);
 944 }
 945
 946 static void
 947 gss_free_ctx(struct gss_cl_ctx *ctx)
 948 {
 949         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 950 }
 951
 952 static void
 953 gss_free_cred(struct gss_cred *gss_cred)
 954 {
 955         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 956         kfree(gss_cred);
 957 }
 958
 959 static void
 960 gss_free_cred_callback(struct rcu_head *head)
 961 {
 962         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 963         gss_free_cred(gss_cred);
 964 }
 965
 966 static void
 967 gss_destroy_nullcred(struct rpc_cred *cred)
 968 {
 969         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 970         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 971         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 972
 973         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 974         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 975         if (ctx)
 976                 gss_put_ctx(ctx);
 977         kref_put(&gss_auth->kref, gss_free_callback);
 978 }
 979
 980 static void
 981 gss_destroy_cred(struct rpc_cred *cred)
 982 {
 983
 984         if (gss_destroying_context(cred))
 985                 return;
 986         gss_destroy_nullcred(cred);
 987 }
 988
 989 /*
 990  * Lookup RPCSEC_GSS cred for the current process
 991  */
 992 static struct rpc_cred *
 993 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 994 {
 995         return rpcauth_lookup_credcache(auth, acred, flags);
 996 }
 997
 998 static struct rpc_cred *
 999 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1000 {
1001         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1002         struct gss_cred *cred = NULL;
1003         int err = -ENOMEM;
1004
1005         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
1006                 acred->uid, auth->au_flavor);
1007
1008         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1009                 goto out_err;
1010
1011         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1012         /*
1013          * Note: in order to force a call to call_refresh(), we deliberately
1014          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1015          */
1016         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1017         cred->gc_service = gss_auth->service;
1018         cred->gc_machine_cred = acred->machine_cred;
1019         kref_get(&gss_auth->kref);
1020         return &cred->gc_base;
1021
1022 out_err:
1023         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
1024         return ERR_PTR(err);
1025 }
1026
1027 static int
1028 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1029 {
1030         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1031         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1032         int err;
1033
1034         do {
1035                 err = gss_create_upcall(gss_auth, gss_cred);
1036         } while (err == -EAGAIN);
1037         return err;
1038 }
1039
1040 static int
1041 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1042 {
1043         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1044
1045         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1046                 goto out;
1047         /* Don't match with creds that have expired. */
1048         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1049                 return 0;
1050         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1051                 return 0;
1052 out:
1053         if (acred->machine_cred != gss_cred->gc_machine_cred)
1054                 return 0;
1055         return rc->cr_uid == acred->uid;
1056 }
1057
1058 /*
1059 * Marshal credentials.
1060 * Maybe we should keep a cached credential for performance reasons.
1061 */
1062 static __be32 *
1063 gss_marshal(struct rpc_task *task, __be32 *p)
1064 {
1065         struct rpc_rqst *req = task->tk_rqstp;
1066         struct rpc_cred *cred = req->rq_cred;
1067         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1068                                                  gc_base);
1069         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1070         __be32          *cred_len;
1071         u32             maj_stat = 0;
1072         struct xdr_netobj mic;
1073         struct kvec     iov;
1074         struct xdr_buf  verf_buf;
1075
1076         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
1077
1078         *p++ = htonl(RPC_AUTH_GSS);
1079         cred_len = p++;
1080
1081         spin_lock(&ctx->gc_seq_lock);
1082         req->rq_seqno = ctx->gc_seq++;
1083         spin_unlock(&ctx->gc_seq_lock);
1084
1085         *p++ = htonl((u32) RPC_GSS_VERSION);
1086         *p++ = htonl((u32) ctx->gc_proc);
1087         *p++ = htonl((u32) req->rq_seqno);
1088         *p++ = htonl((u32) gss_cred->gc_service);
1089         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1090         *cred_len = htonl((p - (cred_len + 1)) << 2);
1091
1092         /* We compute the checksum for the verifier over the xdr-encoded bytes
1093          * starting with the xid and ending at the end of the credential: */
1094         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
1095                                         req->rq_snd_buf.head[0].iov_base);
1096         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1097         xdr_buf_from_iov(&iov, &verf_buf);
1098
1099         /* set verifier flavor*/
1100         *p++ = htonl(RPC_AUTH_GSS);
1101
1102         mic.data = (u8 *)(p + 1);
1103         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1104         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1105                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1106         } else if (maj_stat != 0) {
1107                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1108                 goto out_put_ctx;
1109         }
1110         p = xdr_encode_opaque(p, NULL, mic.len);
1111         gss_put_ctx(ctx);
1112         return p;
1113 out_put_ctx:
1114         gss_put_ctx(ctx);
1115         return NULL;
1116 }
1117
1118 static int gss_renew_cred(struct rpc_task *task)
1119 {
1120         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1121         struct gss_cred *gss_cred = container_of(oldcred,
1122                                                  struct gss_cred,
1123                                                  gc_base);
1124         struct rpc_auth *auth = oldcred->cr_auth;
1125         struct auth_cred acred = {
1126                 .uid = oldcred->cr_uid,
1127                 .machine_cred = gss_cred->gc_machine_cred,
1128         };
1129         struct rpc_cred *new;
1130
1131         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1132         if (IS_ERR(new))
1133                 return PTR_ERR(new);
1134         task->tk_rqstp->rq_cred = new;
1135         put_rpccred(oldcred);
1136         return 0;
1137 }
1138
1139 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1140 {
1141         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1142                 unsigned long now = jiffies;
1143                 unsigned long begin, expire;
1144                 struct gss_cred *gss_cred;
1145
1146                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1147                 begin = gss_cred->gc_upcall_timestamp;
1148                 expire = begin + gss_expired_cred_retry_delay * HZ;
1149
1150                 if (time_in_range_open(now, begin, expire))
1151                         return 1;
1152         }
1153         return 0;
1154 }
1155
1156 /*
1157 * Refresh credentials. XXX - finish
1158 */
1159 static int
1160 gss_refresh(struct rpc_task *task)
1161 {
1162         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1163         int ret = 0;
1164
1165         if (gss_cred_is_negative_entry(cred))
1166                 return -EKEYEXPIRED;
1167
1168         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1169                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1170                 ret = gss_renew_cred(task);
1171                 if (ret < 0)
1172                         goto out;
1173                 cred = task->tk_rqstp->rq_cred;
1174         }
1175
1176         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1177                 ret = gss_refresh_upcall(task);
1178 out:
1179         return ret;
1180 }
1181
1182 /* Dummy refresh routine: used only when destroying the context */
1183 static int
1184 gss_refresh_null(struct rpc_task *task)
1185 {
1186         return -EACCES;
1187 }
1188
1189 static __be32 *
1190 gss_validate(struct rpc_task *task, __be32 *p)
1191 {
1192         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1193         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1194         __be32          seq;
1195         struct kvec     iov;
1196         struct xdr_buf  verf_buf;
1197         struct xdr_netobj mic;
1198         u32             flav,len;
1199         u32             maj_stat;
1200
1201         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
1202
1203         flav = ntohl(*p++);
1204         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1205                 goto out_bad;
1206         if (flav != RPC_AUTH_GSS)
1207                 goto out_bad;
1208         seq = htonl(task->tk_rqstp->rq_seqno);
1209         iov.iov_base = &seq;
1210         iov.iov_len = sizeof(seq);
1211         xdr_buf_from_iov(&iov, &verf_buf);
1212         mic.data = (u8 *)p;
1213         mic.len = len;
1214
1215         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1216         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1217                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1218         if (maj_stat) {
1219                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1220                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1221                 goto out_bad;
1222         }
1223         /* We leave it to unwrap to calculate au_rslack. For now we just
1224          * calculate the length of the verifier: */
1225         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1226         gss_put_ctx(ctx);
1227         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1228                         task->tk_pid);
1229         return p + XDR_QUADLEN(len);
1230 out_bad:
1231         gss_put_ctx(ctx);
1232         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1233         return NULL;
1234 }
1235
1236 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1237                                 __be32 *p, void *obj)
1238 {
1239         struct xdr_stream xdr;
1240
1241         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1242         encode(rqstp, &xdr, obj);
1243 }
1244
1245 static inline int
1246 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1247                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1248                    __be32 *p, void *obj)
1249 {
1250         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1251         struct xdr_buf  integ_buf;
1252         __be32          *integ_len = NULL;
1253         struct xdr_netobj mic;
1254         u32             offset;
1255         __be32          *q;
1256         struct kvec     *iov;
1257         u32             maj_stat = 0;
1258         int             status = -EIO;
1259
1260         integ_len = p++;
1261         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1262         *p++ = htonl(rqstp->rq_seqno);
1263
1264         gss_wrap_req_encode(encode, rqstp, p, obj);
1265
1266         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1267                                 offset, snd_buf->len - offset))
1268                 return status;
1269         *integ_len = htonl(integ_buf.len);
1270
1271         /* guess whether we're in the head or the tail: */
1272         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1273                 iov = snd_buf->tail;
1274         else
1275                 iov = snd_buf->head;
1276         p = iov->iov_base + iov->iov_len;
1277         mic.data = (u8 *)(p + 1);
1278
1279         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1280         status = -EIO; /* XXX? */
1281         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1282                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1283         else if (maj_stat)
1284                 return status;
1285         q = xdr_encode_opaque(p, NULL, mic.len);
1286
1287         offset = (u8 *)q - (u8 *)p;
1288         iov->iov_len += offset;
1289         snd_buf->len += offset;
1290         return 0;
1291 }
1292
1293 static void
1294 priv_release_snd_buf(struct rpc_rqst *rqstp)
1295 {
1296         int i;
1297
1298         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1299                 __free_page(rqstp->rq_enc_pages[i]);
1300         kfree(rqstp->rq_enc_pages);
1301 }
1302
1303 static int
1304 alloc_enc_pages(struct rpc_rqst *rqstp)
1305 {
1306         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1307         int first, last, i;
1308
1309         if (snd_buf->page_len == 0) {
1310                 rqstp->rq_enc_pages_num = 0;
1311                 return 0;
1312         }
1313
1314         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1315         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1316         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1317         rqstp->rq_enc_pages
1318                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1319                                 GFP_NOFS);
1320         if (!rqstp->rq_enc_pages)
1321                 goto out;
1322         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1323                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1324                 if (rqstp->rq_enc_pages[i] == NULL)
1325                         goto out_free;
1326         }
1327         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1328         return 0;
1329 out_free:
1330         rqstp->rq_enc_pages_num = i;
1331         priv_release_snd_buf(rqstp);
1332 out:
1333         return -EAGAIN;
1334 }
1335
1336 static inline int
1337 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1338                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1339                   __be32 *p, void *obj)
1340 {
1341         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1342         u32             offset;
1343         u32             maj_stat;
1344         int             status;
1345         __be32          *opaque_len;
1346         struct page     **inpages;
1347         int             first;
1348         int             pad;
1349         struct kvec     *iov;
1350         char            *tmp;
1351
1352         opaque_len = p++;
1353         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1354         *p++ = htonl(rqstp->rq_seqno);
1355
1356         gss_wrap_req_encode(encode, rqstp, p, obj);
1357
1358         status = alloc_enc_pages(rqstp);
1359         if (status)
1360                 return status;
1361         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1362         inpages = snd_buf->pages + first;
1363         snd_buf->pages = rqstp->rq_enc_pages;
1364         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1365         /*
1366          * Give the tail its own page, in case we need extra space in the
1367          * head when wrapping:
1368          *
1369          * call_allocate() allocates twice the slack space required
1370          * by the authentication flavor to rq_callsize.
1371          * For GSS, slack is GSS_CRED_SLACK.
1372          */
1373         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1374                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1375                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1376                 snd_buf->tail[0].iov_base = tmp;
1377         }
1378         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1379         /* slack space should prevent this ever happening: */
1380         BUG_ON(snd_buf->len > snd_buf->buflen);
1381         status = -EIO;
1382         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1383          * done anyway, so it's safe to put the request on the wire: */
1384         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1385                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1386         else if (maj_stat)
1387                 return status;
1388
1389         *opaque_len = htonl(snd_buf->len - offset);
1390         /* guess whether we're in the head or the tail: */
1391         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1392                 iov = snd_buf->tail;
1393         else
1394                 iov = snd_buf->head;
1395         p = iov->iov_base + iov->iov_len;
1396         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1397         memset(p, 0, pad);
1398         iov->iov_len += pad;
1399         snd_buf->len += pad;
1400
1401         return 0;
1402 }
1403
1404 static int
1405 gss_wrap_req(struct rpc_task *task,
1406              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1407 {
1408         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1409         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1410                         gc_base);
1411         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1412         int             status = -EIO;
1413
1414         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1415         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1416                 /* The spec seems a little ambiguous here, but I think that not
1417                  * wrapping context destruction requests makes the most sense.
1418                  */
1419                 gss_wrap_req_encode(encode, rqstp, p, obj);
1420                 status = 0;
1421                 goto out;
1422         }
1423         switch (gss_cred->gc_service) {
1424                 case RPC_GSS_SVC_NONE:
1425                         gss_wrap_req_encode(encode, rqstp, p, obj);
1426                         status = 0;
1427                         break;
1428                 case RPC_GSS_SVC_INTEGRITY:
1429                         status = gss_wrap_req_integ(cred, ctx, encode,
1430                                                                 rqstp, p, obj);
1431                         break;
1432                 case RPC_GSS_SVC_PRIVACY:
1433                         status = gss_wrap_req_priv(cred, ctx, encode,
1434                                         rqstp, p, obj);
1435                         break;
1436         }
1437 out:
1438         gss_put_ctx(ctx);
1439         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1440         return status;
1441 }
1442
1443 static inline int
1444 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1445                 struct rpc_rqst *rqstp, __be32 **p)
1446 {
1447         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1448         struct xdr_buf integ_buf;
1449         struct xdr_netobj mic;
1450         u32 data_offset, mic_offset;
1451         u32 integ_len;
1452         u32 maj_stat;
1453         int status = -EIO;
1454
1455         integ_len = ntohl(*(*p)++);
1456         if (integ_len & 3)
1457                 return status;
1458         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1459         mic_offset = integ_len + data_offset;
1460         if (mic_offset > rcv_buf->len)
1461                 return status;
1462         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1463                 return status;
1464
1465         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1466                                 mic_offset - data_offset))
1467                 return status;
1468
1469         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1470                 return status;
1471
1472         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1473         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1474                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1475         if (maj_stat != GSS_S_COMPLETE)
1476                 return status;
1477         return 0;
1478 }
1479
1480 static inline int
1481 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1482                 struct rpc_rqst *rqstp, __be32 **p)
1483 {
1484         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1485         u32 offset;
1486         u32 opaque_len;
1487         u32 maj_stat;
1488         int status = -EIO;
1489
1490         opaque_len = ntohl(*(*p)++);
1491         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1492         if (offset + opaque_len > rcv_buf->len)
1493                 return status;
1494         /* remove padding: */
1495         rcv_buf->len = offset + opaque_len;
1496
1497         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1498         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1499                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1500         if (maj_stat != GSS_S_COMPLETE)
1501                 return status;
1502         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1503                 return status;
1504
1505         return 0;
1506 }
1507
1508 static int
1509 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1510                       __be32 *p, void *obj)
1511 {
1512         struct xdr_stream xdr;
1513
1514         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1515         return decode(rqstp, &xdr, obj);
1516 }
1517
1518 static int
1519 gss_unwrap_resp(struct rpc_task *task,
1520                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1521 {
1522         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1523         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1524                         gc_base);
1525         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1526         __be32          *savedp = p;
1527         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1528         int             savedlen = head->iov_len;
1529         int             status = -EIO;
1530
1531         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1532                 goto out_decode;
1533         switch (gss_cred->gc_service) {
1534                 case RPC_GSS_SVC_NONE:
1535                         break;
1536                 case RPC_GSS_SVC_INTEGRITY:
1537                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1538                         if (status)
1539                                 goto out;
1540                         break;
1541                 case RPC_GSS_SVC_PRIVACY:
1542                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1543                         if (status)
1544                                 goto out;
1545                         break;
1546         }
1547         /* take into account extra slack for integrity and privacy cases: */
1548         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1549                                                 + (savedlen - head->iov_len);
1550 out_decode:
1551         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1552 out:
1553         gss_put_ctx(ctx);
1554         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1555                         status);
1556         return status;
1557 }
1558
1559 static const struct rpc_authops authgss_ops = {
1560         .owner          = THIS_MODULE,
1561         .au_flavor      = RPC_AUTH_GSS,
1562         .au_name        = "RPCSEC_GSS",
1563         .create         = gss_create,
1564         .destroy        = gss_destroy,
1565         .lookup_cred    = gss_lookup_cred,
1566         .crcreate       = gss_create_cred
1567 };
1568
1569 static const struct rpc_credops gss_credops = {
1570         .cr_name        = "AUTH_GSS",
1571         .crdestroy      = gss_destroy_cred,
1572         .cr_init        = gss_cred_init,
1573         .crbind         = rpcauth_generic_bind_cred,
1574         .crmatch        = gss_match,
1575         .crmarshal      = gss_marshal,
1576         .crrefresh      = gss_refresh,
1577         .crvalidate     = gss_validate,
1578         .crwrap_req     = gss_wrap_req,
1579         .crunwrap_resp  = gss_unwrap_resp,
1580 };
1581
1582 static const struct rpc_credops gss_nullops = {
1583         .cr_name        = "AUTH_GSS",
1584         .crdestroy      = gss_destroy_nullcred,
1585         .crbind         = rpcauth_generic_bind_cred,
1586         .crmatch        = gss_match,
1587         .crmarshal      = gss_marshal,
1588         .crrefresh      = gss_refresh_null,
1589         .crvalidate     = gss_validate,
1590         .crwrap_req     = gss_wrap_req,
1591         .crunwrap_resp  = gss_unwrap_resp,
1592 };
1593
1594 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1595         .upcall         = gss_pipe_upcall,
1596         .downcall       = gss_pipe_downcall,
1597         .destroy_msg    = gss_pipe_destroy_msg,
1598         .open_pipe      = gss_pipe_open_v0,
1599         .release_pipe   = gss_pipe_release,
1600 };
1601
1602 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1603         .upcall         = gss_pipe_upcall,
1604         .downcall       = gss_pipe_downcall,
1605         .destroy_msg    = gss_pipe_destroy_msg,
1606         .open_pipe      = gss_pipe_open_v1,
1607         .release_pipe   = gss_pipe_release,
1608 };
1609
1610 /*
1611  * Initialize RPCSEC_GSS module
1612  */
1613 static int __init init_rpcsec_gss(void)
1614 {
1615         int err = 0;
1616
1617         err = rpcauth_register(&authgss_ops);
1618         if (err)
1619                 goto out;
1620         err = gss_svc_init();
1621         if (err)
1622                 goto out_unregister;
1623         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1624         return 0;
1625 out_unregister:
1626         rpcauth_unregister(&authgss_ops);
1627 out:
1628         return err;
1629 }
1630
1631 static void __exit exit_rpcsec_gss(void)
1632 {
1633         gss_svc_shutdown();
1634         rpcauth_unregister(&authgss_ops);
1635         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1636 }
1637
1638 MODULE_LICENSE("GPL");
1639 module_param_named(expired_cred_retry_delay,
1640                    gss_expired_cred_retry_delay,
1641                    uint, 0644);
1642 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
1643                 "the RPC engine retries an expired credential");
1644
1645 module_init(init_rpcsec_gss)
1646 module_exit(exit_rpcsec_gss)