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, 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 0;
 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 (err)
 567                         goto out;
 568                 if (pipe_version < 0)
 569                         warn_gssd();
 570                 goto retry;
 571         }
 572         if (IS_ERR(gss_msg)) {
 573                 err = PTR_ERR(gss_msg);
 574                 goto out;
 575         }
 576         inode = &gss_msg->inode->vfs_inode;
 577         for (;;) {
 578                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 579                 spin_lock(&inode->i_lock);
 580                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 581                         break;
 582                 }
 583                 spin_unlock(&inode->i_lock);
 584                 if (signalled()) {
 585                         err = -ERESTARTSYS;
 586                         goto out_intr;
 587                 }
 588                 schedule();
 589         }
 590         if (gss_msg->ctx)
 591                 gss_cred_set_ctx(cred, gss_msg->ctx);
 592         else
 593                 err = gss_msg->msg.errno;
 594         spin_unlock(&inode->i_lock);
 595 out_intr:
 596         finish_wait(&gss_msg->waitqueue, &wait);
 597         gss_release_msg(gss_msg);
 598 out:
 599         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 600                         cred->cr_uid, err);
 601         return err;
 602 }
 603
 604 static ssize_t
 605 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 606                 char __user *dst, size_t buflen)
 607 {
 608         char *data = (char *)msg->data + msg->copied;
 609         size_t mlen = min(msg->len, buflen);
 610         unsigned long left;
 611
 612         left = copy_to_user(dst, data, mlen);
 613         if (left == mlen) {
 614                 msg->errno = -EFAULT;
 615                 return -EFAULT;
 616         }
 617
 618         mlen -= left;
 619         msg->copied += mlen;
 620         msg->errno = 0;
 621         return mlen;
 622 }
 623
 624 #define MSG_BUF_MAXSIZE 1024
 625
 626 static ssize_t
 627 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 628 {
 629         const void *p, *end;
 630         void *buf;
 631         struct gss_upcall_msg *gss_msg;
 632         struct inode *inode = filp->f_path.dentry->d_inode;
 633         struct gss_cl_ctx *ctx;
 634         uid_t uid;
 635         ssize_t err = -EFBIG;
 636
 637         if (mlen > MSG_BUF_MAXSIZE)
 638                 goto out;
 639         err = -ENOMEM;
 640         buf = kmalloc(mlen, GFP_NOFS);
 641         if (!buf)
 642                 goto out;
 643
 644         err = -EFAULT;
 645         if (copy_from_user(buf, src, mlen))
 646                 goto err;
 647
 648         end = (const void *)((char *)buf + mlen);
 649         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 650         if (IS_ERR(p)) {
 651                 err = PTR_ERR(p);
 652                 goto err;
 653         }
 654
 655         err = -ENOMEM;
 656         ctx = gss_alloc_context();
 657         if (ctx == NULL)
 658                 goto err;
 659
 660         err = -ENOENT;
 661         /* Find a matching upcall */
 662         spin_lock(&inode->i_lock);
 663         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 664         if (gss_msg == NULL) {
 665                 spin_unlock(&inode->i_lock);
 666                 goto err_put_ctx;
 667         }
 668         list_del_init(&gss_msg->list);
 669         spin_unlock(&inode->i_lock);
 670
 671         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 672         if (IS_ERR(p)) {
 673                 err = PTR_ERR(p);
 674                 switch (err) {
 675                 case -EACCES:
 676                 case -EKEYEXPIRED:
 677                         gss_msg->msg.errno = err;
 678                         err = mlen;
 679                         break;
 680                 case -EFAULT:
 681                 case -ENOMEM:
 682                 case -EINVAL:
 683                 case -ENOSYS:
 684                         gss_msg->msg.errno = -EAGAIN;
 685                         break;
 686                 default:
 687                         printk(KERN_CRIT "%s: bad return from "
 688                                 "gss_fill_context: %zd\n", __func__, err);
 689                         BUG();
 690                 }
 691                 goto err_release_msg;
 692         }
 693         gss_msg->ctx = gss_get_ctx(ctx);
 694         err = mlen;
 695
 696 err_release_msg:
 697         spin_lock(&inode->i_lock);
 698         __gss_unhash_msg(gss_msg);
 699         spin_unlock(&inode->i_lock);
 700         gss_release_msg(gss_msg);
 701 err_put_ctx:
 702         gss_put_ctx(ctx);
 703 err:
 704         kfree(buf);
 705 out:
 706         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 707         return err;
 708 }
 709
 710 static int gss_pipe_open(struct inode *inode, int new_version)
 711 {
 712         int ret = 0;
 713
 714         spin_lock(&pipe_version_lock);
 715         if (pipe_version < 0) {
 716                 /* First open of any gss pipe determines the version: */
 717                 pipe_version = new_version;
 718                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 719                 wake_up(&pipe_version_waitqueue);
 720         } else if (pipe_version != new_version) {
 721                 /* Trying to open a pipe of a different version */
 722                 ret = -EBUSY;
 723                 goto out;
 724         }
 725         atomic_inc(&pipe_users);
 726 out:
 727         spin_unlock(&pipe_version_lock);
 728         return ret;
 729
 730 }
 731
 732 static int gss_pipe_open_v0(struct inode *inode)
 733 {
 734         return gss_pipe_open(inode, 0);
 735 }
 736
 737 static int gss_pipe_open_v1(struct inode *inode)
 738 {
 739         return gss_pipe_open(inode, 1);
 740 }
 741
 742 static void
 743 gss_pipe_release(struct inode *inode)
 744 {
 745         struct rpc_inode *rpci = RPC_I(inode);
 746         struct gss_upcall_msg *gss_msg;
 747
 748         spin_lock(&inode->i_lock);
 749         while (!list_empty(&rpci->in_downcall)) {
 750
 751                 gss_msg = list_entry(rpci->in_downcall.next,
 752                                 struct gss_upcall_msg, list);
 753                 gss_msg->msg.errno = -EPIPE;
 754                 atomic_inc(&gss_msg->count);
 755                 __gss_unhash_msg(gss_msg);
 756                 spin_unlock(&inode->i_lock);
 757                 gss_release_msg(gss_msg);
 758                 spin_lock(&inode->i_lock);
 759         }
 760         spin_unlock(&inode->i_lock);
 761
 762         put_pipe_version();
 763 }
 764
 765 static void
 766 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 767 {
 768         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 769
 770         if (msg->errno < 0) {
 771                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 772                                 gss_msg);
 773                 atomic_inc(&gss_msg->count);
 774                 gss_unhash_msg(gss_msg);
 775                 if (msg->errno == -ETIMEDOUT)
 776                         warn_gssd();
 777                 gss_release_msg(gss_msg);
 778         }
 779 }
 780
 781 /*
 782  * NOTE: we have the opportunity to use different
 783  * parameters based on the input flavor (which must be a pseudoflavor)
 784  */
 785 static struct rpc_auth *
 786 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 787 {
 788         struct gss_auth *gss_auth;
 789         struct rpc_auth * auth;
 790         int err = -ENOMEM; /* XXX? */
 791
 792         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 793
 794         if (!try_module_get(THIS_MODULE))
 795                 return ERR_PTR(err);
 796         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 797                 goto out_dec;
 798         gss_auth->client = clnt;
 799         err = -EINVAL;
 800         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 801         if (!gss_auth->mech) {
 802                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 803                                 __func__, flavor);
 804                 goto err_free;
 805         }
 806         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 807         if (gss_auth->service == 0)
 808                 goto err_put_mech;
 809         auth = &gss_auth->rpc_auth;
 810         auth->au_cslack = GSS_CRED_SLACK >> 2;
 811         auth->au_rslack = GSS_VERF_SLACK >> 2;
 812         auth->au_ops = &authgss_ops;
 813         auth->au_flavor = flavor;
 814         atomic_set(&auth->au_count, 1);
 815         kref_init(&gss_auth->kref);
 816
 817         /*
 818          * Note: if we created the old pipe first, then someone who
 819          * examined the directory at the right moment might conclude
 820          * that we supported only the old pipe.  So we instead create
 821          * the new pipe first.
 822          */
 823         gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry,
 824                                          "gssd",
 825                                          clnt, &gss_upcall_ops_v1,
 826                                          RPC_PIPE_WAIT_FOR_OPEN);
 827         if (IS_ERR(gss_auth->dentry[1])) {
 828                 err = PTR_ERR(gss_auth->dentry[1]);
 829                 goto err_put_mech;
 830         }
 831
 832         gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry,
 833                                          gss_auth->mech->gm_name,
 834                                          clnt, &gss_upcall_ops_v0,
 835                                          RPC_PIPE_WAIT_FOR_OPEN);
 836         if (IS_ERR(gss_auth->dentry[0])) {
 837                 err = PTR_ERR(gss_auth->dentry[0]);
 838                 goto err_unlink_pipe_1;
 839         }
 840         err = rpcauth_init_credcache(auth);
 841         if (err)
 842                 goto err_unlink_pipe_0;
 843
 844         return auth;
 845 err_unlink_pipe_0:
 846         rpc_unlink(gss_auth->dentry[0]);
 847 err_unlink_pipe_1:
 848         rpc_unlink(gss_auth->dentry[1]);
 849 err_put_mech:
 850         gss_mech_put(gss_auth->mech);
 851 err_free:
 852         kfree(gss_auth);
 853 out_dec:
 854         module_put(THIS_MODULE);
 855         return ERR_PTR(err);
 856 }
 857
 858 static void
 859 gss_free(struct gss_auth *gss_auth)
 860 {
 861         rpc_unlink(gss_auth->dentry[1]);
 862         rpc_unlink(gss_auth->dentry[0]);
 863         gss_mech_put(gss_auth->mech);
 864
 865         kfree(gss_auth);
 866         module_put(THIS_MODULE);
 867 }
 868
 869 static void
 870 gss_free_callback(struct kref *kref)
 871 {
 872         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 873
 874         gss_free(gss_auth);
 875 }
 876
 877 static void
 878 gss_destroy(struct rpc_auth *auth)
 879 {
 880         struct gss_auth *gss_auth;
 881
 882         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 883                         auth, auth->au_flavor);
 884
 885         rpcauth_destroy_credcache(auth);
 886
 887         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 888         kref_put(&gss_auth->kref, gss_free_callback);
 889 }
 890
 891 /*
 892  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 893  * to the server with the GSS control procedure field set to
 894  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 895  * all RPCSEC_GSS state associated with that context.
 896  */
 897 static int
 898 gss_destroying_context(struct rpc_cred *cred)
 899 {
 900         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 901         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 902         struct rpc_task *task;
 903
 904         if (gss_cred->gc_ctx == NULL ||
 905             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 906                 return 0;
 907
 908         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 909         cred->cr_ops = &gss_nullops;
 910
 911         /* Take a reference to ensure the cred will be destroyed either
 912          * by the RPC call or by the put_rpccred() below */
 913         get_rpccred(cred);
 914
 915         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 916         if (!IS_ERR(task))
 917                 rpc_put_task(task);
 918
 919         put_rpccred(cred);
 920         return 1;
 921 }
 922
 923 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 924  * to create a new cred or context, so they check that things have been
 925  * allocated before freeing them. */
 926 static void
 927 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 928 {
 929         dprintk("RPC:       gss_free_ctx\n");
 930
 931         gss_delete_sec_context(&ctx->gc_gss_ctx);
 932         kfree(ctx->gc_wire_ctx.data);
 933         kfree(ctx);
 934 }
 935
 936 static void
 937 gss_free_ctx_callback(struct rcu_head *head)
 938 {
 939         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 940         gss_do_free_ctx(ctx);
 941 }
 942
 943 static void
 944 gss_free_ctx(struct gss_cl_ctx *ctx)
 945 {
 946         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 947 }
 948
 949 static void
 950 gss_free_cred(struct gss_cred *gss_cred)
 951 {
 952         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 953         kfree(gss_cred);
 954 }
 955
 956 static void
 957 gss_free_cred_callback(struct rcu_head *head)
 958 {
 959         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 960         gss_free_cred(gss_cred);
 961 }
 962
 963 static void
 964 gss_destroy_nullcred(struct rpc_cred *cred)
 965 {
 966         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 967         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 968         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 969
 970         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 971         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 972         if (ctx)
 973                 gss_put_ctx(ctx);
 974         kref_put(&gss_auth->kref, gss_free_callback);
 975 }
 976
 977 static void
 978 gss_destroy_cred(struct rpc_cred *cred)
 979 {
 980
 981         if (gss_destroying_context(cred))
 982                 return;
 983         gss_destroy_nullcred(cred);
 984 }
 985
 986 /*
 987  * Lookup RPCSEC_GSS cred for the current process
 988  */
 989 static struct rpc_cred *
 990 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 991 {
 992         return rpcauth_lookup_credcache(auth, acred, flags);
 993 }
 994
 995 static struct rpc_cred *
 996 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 997 {
 998         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 999         struct gss_cred *cred = NULL;
1000         int err = -ENOMEM;
1001
1002         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
1003                 acred->uid, auth->au_flavor);
1004
1005         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1006                 goto out_err;
1007
1008         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1009         /*
1010          * Note: in order to force a call to call_refresh(), we deliberately
1011          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1012          */
1013         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1014         cred->gc_service = gss_auth->service;
1015         cred->gc_machine_cred = acred->machine_cred;
1016         kref_get(&gss_auth->kref);
1017         return &cred->gc_base;
1018
1019 out_err:
1020         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
1021         return ERR_PTR(err);
1022 }
1023
1024 static int
1025 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1026 {
1027         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1028         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1029         int err;
1030
1031         do {
1032                 err = gss_create_upcall(gss_auth, gss_cred);
1033         } while (err == -EAGAIN);
1034         return err;
1035 }
1036
1037 static int
1038 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1039 {
1040         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1041
1042         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1043                 goto out;
1044         /* Don't match with creds that have expired. */
1045         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1046                 return 0;
1047         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1048                 return 0;
1049 out:
1050         if (acred->machine_cred != gss_cred->gc_machine_cred)
1051                 return 0;
1052         return rc->cr_uid == acred->uid;
1053 }
1054
1055 /*
1056 * Marshal credentials.
1057 * Maybe we should keep a cached credential for performance reasons.
1058 */
1059 static __be32 *
1060 gss_marshal(struct rpc_task *task, __be32 *p)
1061 {
1062         struct rpc_rqst *req = task->tk_rqstp;
1063         struct rpc_cred *cred = req->rq_cred;
1064         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1065                                                  gc_base);
1066         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1067         __be32          *cred_len;
1068         u32             maj_stat = 0;
1069         struct xdr_netobj mic;
1070         struct kvec     iov;
1071         struct xdr_buf  verf_buf;
1072
1073         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
1074
1075         *p++ = htonl(RPC_AUTH_GSS);
1076         cred_len = p++;
1077
1078         spin_lock(&ctx->gc_seq_lock);
1079         req->rq_seqno = ctx->gc_seq++;
1080         spin_unlock(&ctx->gc_seq_lock);
1081
1082         *p++ = htonl((u32) RPC_GSS_VERSION);
1083         *p++ = htonl((u32) ctx->gc_proc);
1084         *p++ = htonl((u32) req->rq_seqno);
1085         *p++ = htonl((u32) gss_cred->gc_service);
1086         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1087         *cred_len = htonl((p - (cred_len + 1)) << 2);
1088
1089         /* We compute the checksum for the verifier over the xdr-encoded bytes
1090          * starting with the xid and ending at the end of the credential: */
1091         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
1092                                         req->rq_snd_buf.head[0].iov_base);
1093         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1094         xdr_buf_from_iov(&iov, &verf_buf);
1095
1096         /* set verifier flavor*/
1097         *p++ = htonl(RPC_AUTH_GSS);
1098
1099         mic.data = (u8 *)(p + 1);
1100         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1101         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1102                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1103         } else if (maj_stat != 0) {
1104                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1105                 goto out_put_ctx;
1106         }
1107         p = xdr_encode_opaque(p, NULL, mic.len);
1108         gss_put_ctx(ctx);
1109         return p;
1110 out_put_ctx:
1111         gss_put_ctx(ctx);
1112         return NULL;
1113 }
1114
1115 static int gss_renew_cred(struct rpc_task *task)
1116 {
1117         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1118         struct gss_cred *gss_cred = container_of(oldcred,
1119                                                  struct gss_cred,
1120                                                  gc_base);
1121         struct rpc_auth *auth = oldcred->cr_auth;
1122         struct auth_cred acred = {
1123                 .uid = oldcred->cr_uid,
1124                 .machine_cred = gss_cred->gc_machine_cred,
1125         };
1126         struct rpc_cred *new;
1127
1128         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1129         if (IS_ERR(new))
1130                 return PTR_ERR(new);
1131         task->tk_rqstp->rq_cred = new;
1132         put_rpccred(oldcred);
1133         return 0;
1134 }
1135
1136 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1137 {
1138         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1139                 unsigned long now = jiffies;
1140                 unsigned long begin, expire;
1141                 struct gss_cred *gss_cred;
1142
1143                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1144                 begin = gss_cred->gc_upcall_timestamp;
1145                 expire = begin + gss_expired_cred_retry_delay * HZ;
1146
1147                 if (time_in_range_open(now, begin, expire))
1148                         return 1;
1149         }
1150         return 0;
1151 }
1152
1153 /*
1154 * Refresh credentials. XXX - finish
1155 */
1156 static int
1157 gss_refresh(struct rpc_task *task)
1158 {
1159         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1160         int ret = 0;
1161
1162         if (gss_cred_is_negative_entry(cred))
1163                 return -EKEYEXPIRED;
1164
1165         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1166                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1167                 ret = gss_renew_cred(task);
1168                 if (ret < 0)
1169                         goto out;
1170                 cred = task->tk_rqstp->rq_cred;
1171         }
1172
1173         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1174                 ret = gss_refresh_upcall(task);
1175 out:
1176         return ret;
1177 }
1178
1179 /* Dummy refresh routine: used only when destroying the context */
1180 static int
1181 gss_refresh_null(struct rpc_task *task)
1182 {
1183         return -EACCES;
1184 }
1185
1186 static __be32 *
1187 gss_validate(struct rpc_task *task, __be32 *p)
1188 {
1189         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1190         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1191         __be32          seq;
1192         struct kvec     iov;
1193         struct xdr_buf  verf_buf;
1194         struct xdr_netobj mic;
1195         u32             flav,len;
1196         u32             maj_stat;
1197
1198         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
1199
1200         flav = ntohl(*p++);
1201         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1202                 goto out_bad;
1203         if (flav != RPC_AUTH_GSS)
1204                 goto out_bad;
1205         seq = htonl(task->tk_rqstp->rq_seqno);
1206         iov.iov_base = &seq;
1207         iov.iov_len = sizeof(seq);
1208         xdr_buf_from_iov(&iov, &verf_buf);
1209         mic.data = (u8 *)p;
1210         mic.len = len;
1211
1212         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1213         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1214                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1215         if (maj_stat) {
1216                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1217                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1218                 goto out_bad;
1219         }
1220         /* We leave it to unwrap to calculate au_rslack. For now we just
1221          * calculate the length of the verifier: */
1222         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1223         gss_put_ctx(ctx);
1224         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1225                         task->tk_pid);
1226         return p + XDR_QUADLEN(len);
1227 out_bad:
1228         gss_put_ctx(ctx);
1229         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1230         return NULL;
1231 }
1232
1233 static inline int
1234 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1235                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1236 {
1237         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1238         struct xdr_buf  integ_buf;
1239         __be32          *integ_len = NULL;
1240         struct xdr_netobj mic;
1241         u32             offset;
1242         __be32          *q;
1243         struct kvec     *iov;
1244         u32             maj_stat = 0;
1245         int             status = -EIO;
1246
1247         integ_len = p++;
1248         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1249         *p++ = htonl(rqstp->rq_seqno);
1250
1251         status = encode(rqstp, p, obj);
1252         if (status)
1253                 return status;
1254
1255         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1256                                 offset, snd_buf->len - offset))
1257                 return status;
1258         *integ_len = htonl(integ_buf.len);
1259
1260         /* guess whether we're in the head or the tail: */
1261         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1262                 iov = snd_buf->tail;
1263         else
1264                 iov = snd_buf->head;
1265         p = iov->iov_base + iov->iov_len;
1266         mic.data = (u8 *)(p + 1);
1267
1268         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1269         status = -EIO; /* XXX? */
1270         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1271                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1272         else if (maj_stat)
1273                 return status;
1274         q = xdr_encode_opaque(p, NULL, mic.len);
1275
1276         offset = (u8 *)q - (u8 *)p;
1277         iov->iov_len += offset;
1278         snd_buf->len += offset;
1279         return 0;
1280 }
1281
1282 static void
1283 priv_release_snd_buf(struct rpc_rqst *rqstp)
1284 {
1285         int i;
1286
1287         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1288                 __free_page(rqstp->rq_enc_pages[i]);
1289         kfree(rqstp->rq_enc_pages);
1290 }
1291
1292 static int
1293 alloc_enc_pages(struct rpc_rqst *rqstp)
1294 {
1295         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1296         int first, last, i;
1297
1298         if (snd_buf->page_len == 0) {
1299                 rqstp->rq_enc_pages_num = 0;
1300                 return 0;
1301         }
1302
1303         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1304         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1305         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1306         rqstp->rq_enc_pages
1307                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1308                                 GFP_NOFS);
1309         if (!rqstp->rq_enc_pages)
1310                 goto out;
1311         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1312                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1313                 if (rqstp->rq_enc_pages[i] == NULL)
1314                         goto out_free;
1315         }
1316         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1317         return 0;
1318 out_free:
1319         rqstp->rq_enc_pages_num = i;
1320         priv_release_snd_buf(rqstp);
1321 out:
1322         return -EAGAIN;
1323 }
1324
1325 static inline int
1326 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1327                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1328 {
1329         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1330         u32             offset;
1331         u32             maj_stat;
1332         int             status;
1333         __be32          *opaque_len;
1334         struct page     **inpages;
1335         int             first;
1336         int             pad;
1337         struct kvec     *iov;
1338         char            *tmp;
1339
1340         opaque_len = p++;
1341         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1342         *p++ = htonl(rqstp->rq_seqno);
1343
1344         status = encode(rqstp, p, obj);
1345         if (status)
1346                 return status;
1347
1348         status = alloc_enc_pages(rqstp);
1349         if (status)
1350                 return status;
1351         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1352         inpages = snd_buf->pages + first;
1353         snd_buf->pages = rqstp->rq_enc_pages;
1354         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1355         /*
1356          * Give the tail its own page, in case we need extra space in the
1357          * head when wrapping:
1358          *
1359          * call_allocate() allocates twice the slack space required
1360          * by the authentication flavor to rq_callsize.
1361          * For GSS, slack is GSS_CRED_SLACK.
1362          */
1363         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1364                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1365                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1366                 snd_buf->tail[0].iov_base = tmp;
1367         }
1368         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1369         /* slack space should prevent this ever happening: */
1370         BUG_ON(snd_buf->len > snd_buf->buflen);
1371         status = -EIO;
1372         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1373          * done anyway, so it's safe to put the request on the wire: */
1374         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1375                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1376         else if (maj_stat)
1377                 return status;
1378
1379         *opaque_len = htonl(snd_buf->len - offset);
1380         /* guess whether we're in the head or the tail: */
1381         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1382                 iov = snd_buf->tail;
1383         else
1384                 iov = snd_buf->head;
1385         p = iov->iov_base + iov->iov_len;
1386         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1387         memset(p, 0, pad);
1388         iov->iov_len += pad;
1389         snd_buf->len += pad;
1390
1391         return 0;
1392 }
1393
1394 static int
1395 gss_wrap_req(struct rpc_task *task,
1396              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1397 {
1398         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1399         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1400                         gc_base);
1401         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1402         int             status = -EIO;
1403
1404         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1405         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1406                 /* The spec seems a little ambiguous here, but I think that not
1407                  * wrapping context destruction requests makes the most sense.
1408                  */
1409                 status = encode(rqstp, p, obj);
1410                 goto out;
1411         }
1412         switch (gss_cred->gc_service) {
1413                 case RPC_GSS_SVC_NONE:
1414                         status = encode(rqstp, p, obj);
1415                         break;
1416                 case RPC_GSS_SVC_INTEGRITY:
1417                         status = gss_wrap_req_integ(cred, ctx, encode,
1418                                                                 rqstp, p, obj);
1419                         break;
1420                 case RPC_GSS_SVC_PRIVACY:
1421                         status = gss_wrap_req_priv(cred, ctx, encode,
1422                                         rqstp, p, obj);
1423                         break;
1424         }
1425 out:
1426         gss_put_ctx(ctx);
1427         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1428         return status;
1429 }
1430
1431 static inline int
1432 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1433                 struct rpc_rqst *rqstp, __be32 **p)
1434 {
1435         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1436         struct xdr_buf integ_buf;
1437         struct xdr_netobj mic;
1438         u32 data_offset, mic_offset;
1439         u32 integ_len;
1440         u32 maj_stat;
1441         int status = -EIO;
1442
1443         integ_len = ntohl(*(*p)++);
1444         if (integ_len & 3)
1445                 return status;
1446         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1447         mic_offset = integ_len + data_offset;
1448         if (mic_offset > rcv_buf->len)
1449                 return status;
1450         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1451                 return status;
1452
1453         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1454                                 mic_offset - data_offset))
1455                 return status;
1456
1457         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1458                 return status;
1459
1460         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1461         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1462                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1463         if (maj_stat != GSS_S_COMPLETE)
1464                 return status;
1465         return 0;
1466 }
1467
1468 static inline int
1469 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1470                 struct rpc_rqst *rqstp, __be32 **p)
1471 {
1472         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1473         u32 offset;
1474         u32 opaque_len;
1475         u32 maj_stat;
1476         int status = -EIO;
1477
1478         opaque_len = ntohl(*(*p)++);
1479         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1480         if (offset + opaque_len > rcv_buf->len)
1481                 return status;
1482         /* remove padding: */
1483         rcv_buf->len = offset + opaque_len;
1484
1485         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1486         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1487                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1488         if (maj_stat != GSS_S_COMPLETE)
1489                 return status;
1490         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1491                 return status;
1492
1493         return 0;
1494 }
1495
1496
1497 static int
1498 gss_unwrap_resp(struct rpc_task *task,
1499                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1500 {
1501         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1502         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1503                         gc_base);
1504         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1505         __be32          *savedp = p;
1506         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1507         int             savedlen = head->iov_len;
1508         int             status = -EIO;
1509
1510         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1511                 goto out_decode;
1512         switch (gss_cred->gc_service) {
1513                 case RPC_GSS_SVC_NONE:
1514                         break;
1515                 case RPC_GSS_SVC_INTEGRITY:
1516                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1517                         if (status)
1518                                 goto out;
1519                         break;
1520                 case RPC_GSS_SVC_PRIVACY:
1521                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1522                         if (status)
1523                                 goto out;
1524                         break;
1525         }
1526         /* take into account extra slack for integrity and privacy cases: */
1527         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1528                                                 + (savedlen - head->iov_len);
1529 out_decode:
1530         status = decode(rqstp, p, obj);
1531 out:
1532         gss_put_ctx(ctx);
1533         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1534                         status);
1535         return status;
1536 }
1537
1538 static const struct rpc_authops authgss_ops = {
1539         .owner          = THIS_MODULE,
1540         .au_flavor      = RPC_AUTH_GSS,
1541         .au_name        = "RPCSEC_GSS",
1542         .create         = gss_create,
1543         .destroy        = gss_destroy,
1544         .lookup_cred    = gss_lookup_cred,
1545         .crcreate       = gss_create_cred
1546 };
1547
1548 static const struct rpc_credops gss_credops = {
1549         .cr_name        = "AUTH_GSS",
1550         .crdestroy      = gss_destroy_cred,
1551         .cr_init        = gss_cred_init,
1552         .crbind         = rpcauth_generic_bind_cred,
1553         .crmatch        = gss_match,
1554         .crmarshal      = gss_marshal,
1555         .crrefresh      = gss_refresh,
1556         .crvalidate     = gss_validate,
1557         .crwrap_req     = gss_wrap_req,
1558         .crunwrap_resp  = gss_unwrap_resp,
1559 };
1560
1561 static const struct rpc_credops gss_nullops = {
1562         .cr_name        = "AUTH_GSS",
1563         .crdestroy      = gss_destroy_nullcred,
1564         .crbind         = rpcauth_generic_bind_cred,
1565         .crmatch        = gss_match,
1566         .crmarshal      = gss_marshal,
1567         .crrefresh      = gss_refresh_null,
1568         .crvalidate     = gss_validate,
1569         .crwrap_req     = gss_wrap_req,
1570         .crunwrap_resp  = gss_unwrap_resp,
1571 };
1572
1573 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1574         .upcall         = gss_pipe_upcall,
1575         .downcall       = gss_pipe_downcall,
1576         .destroy_msg    = gss_pipe_destroy_msg,
1577         .open_pipe      = gss_pipe_open_v0,
1578         .release_pipe   = gss_pipe_release,
1579 };
1580
1581 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1582         .upcall         = gss_pipe_upcall,
1583         .downcall       = gss_pipe_downcall,
1584         .destroy_msg    = gss_pipe_destroy_msg,
1585         .open_pipe      = gss_pipe_open_v1,
1586         .release_pipe   = gss_pipe_release,
1587 };
1588
1589 /*
1590  * Initialize RPCSEC_GSS module
1591  */
1592 static int __init init_rpcsec_gss(void)
1593 {
1594         int err = 0;
1595
1596         err = rpcauth_register(&authgss_ops);
1597         if (err)
1598                 goto out;
1599         err = gss_svc_init();
1600         if (err)
1601                 goto out_unregister;
1602         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1603         return 0;
1604 out_unregister:
1605         rpcauth_unregister(&authgss_ops);
1606 out:
1607         return err;
1608 }
1609
1610 static void __exit exit_rpcsec_gss(void)
1611 {
1612         gss_svc_shutdown();
1613         rpcauth_unregister(&authgss_ops);
1614         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1615 }
1616
1617 MODULE_LICENSE("GPL");
1618 module_param_named(expired_cred_retry_delay,
1619                    gss_expired_cred_retry_delay,
1620                    uint, 0644);
1621 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
1622                 "the RPC engine retries an expired credential");
1623
1624 module_init(init_rpcsec_gss)
1625 module_exit(exit_rpcsec_gss)