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