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