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   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54
  55 static const struct rpc_authops authgss_ops;
  56
  57 static const struct rpc_credops gss_credops;
  58 static const struct rpc_credops gss_nullops;
  59
  60 #ifdef RPC_DEBUG
  61 # define RPCDBG_FACILITY        RPCDBG_AUTH
  62 #endif
  63
  64 #define GSS_CRED_SLACK          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 struct rpc_pipe_ops gss_upcall_ops_v0;
  93 static 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_auth *gss_auth, 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_auth, 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 (IS_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                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 648                 goto err_release_msg;
 649         }
 650         gss_msg->ctx = gss_get_ctx(ctx);
 651         err = mlen;
 652
 653 err_release_msg:
 654         spin_lock(&inode->i_lock);
 655         __gss_unhash_msg(gss_msg);
 656         spin_unlock(&inode->i_lock);
 657         gss_release_msg(gss_msg);
 658 err_put_ctx:
 659         gss_put_ctx(ctx);
 660 err:
 661         kfree(buf);
 662 out:
 663         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 664         return err;
 665 }
 666
 667 static int gss_pipe_open(struct inode *inode, int new_version)
 668 {
 669         int ret = 0;
 670
 671         spin_lock(&pipe_version_lock);
 672         if (pipe_version < 0) {
 673                 /* First open of any gss pipe determines the version: */
 674                 pipe_version = new_version;
 675                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 676                 wake_up(&pipe_version_waitqueue);
 677         } else if (pipe_version != new_version) {
 678                 /* Trying to open a pipe of a different version */
 679                 ret = -EBUSY;
 680                 goto out;
 681         }
 682         atomic_inc(&pipe_users);
 683 out:
 684         spin_unlock(&pipe_version_lock);
 685         return ret;
 686
 687 }
 688
 689 static int gss_pipe_open_v0(struct inode *inode)
 690 {
 691         return gss_pipe_open(inode, 0);
 692 }
 693
 694 static int gss_pipe_open_v1(struct inode *inode)
 695 {
 696         return gss_pipe_open(inode, 1);
 697 }
 698
 699 static void
 700 gss_pipe_release(struct inode *inode)
 701 {
 702         struct rpc_inode *rpci = RPC_I(inode);
 703         struct gss_upcall_msg *gss_msg;
 704
 705         spin_lock(&inode->i_lock);
 706         while (!list_empty(&rpci->in_downcall)) {
 707
 708                 gss_msg = list_entry(rpci->in_downcall.next,
 709                                 struct gss_upcall_msg, list);
 710                 gss_msg->msg.errno = -EPIPE;
 711                 atomic_inc(&gss_msg->count);
 712                 __gss_unhash_msg(gss_msg);
 713                 spin_unlock(&inode->i_lock);
 714                 gss_release_msg(gss_msg);
 715                 spin_lock(&inode->i_lock);
 716         }
 717         spin_unlock(&inode->i_lock);
 718
 719         put_pipe_version();
 720 }
 721
 722 static void
 723 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 724 {
 725         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 726
 727         if (msg->errno < 0) {
 728                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 729                                 gss_msg);
 730                 atomic_inc(&gss_msg->count);
 731                 gss_unhash_msg(gss_msg);
 732                 if (msg->errno == -ETIMEDOUT)
 733                         warn_gssd();
 734                 gss_release_msg(gss_msg);
 735         }
 736 }
 737
 738 /*
 739  * NOTE: we have the opportunity to use different
 740  * parameters based on the input flavor (which must be a pseudoflavor)
 741  */
 742 static struct rpc_auth *
 743 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 744 {
 745         struct gss_auth *gss_auth;
 746         struct rpc_auth * auth;
 747         int err = -ENOMEM; /* XXX? */
 748
 749         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 750
 751         if (!try_module_get(THIS_MODULE))
 752                 return ERR_PTR(err);
 753         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 754                 goto out_dec;
 755         gss_auth->client = clnt;
 756         err = -EINVAL;
 757         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 758         if (!gss_auth->mech) {
 759                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 760                                 __func__, flavor);
 761                 goto err_free;
 762         }
 763         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 764         if (gss_auth->service == 0)
 765                 goto err_put_mech;
 766         auth = &gss_auth->rpc_auth;
 767         auth->au_cslack = GSS_CRED_SLACK >> 2;
 768         auth->au_rslack = GSS_VERF_SLACK >> 2;
 769         auth->au_ops = &authgss_ops;
 770         auth->au_flavor = flavor;
 771         atomic_set(&auth->au_count, 1);
 772         kref_init(&gss_auth->kref);
 773
 774         /*
 775          * Note: if we created the old pipe first, then someone who
 776          * examined the directory at the right moment might conclude
 777          * that we supported only the old pipe.  So we instead create
 778          * the new pipe first.
 779          */
 780         gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_dentry,
 781                                          "gssd",
 782                                          clnt, &gss_upcall_ops_v1,
 783                                          RPC_PIPE_WAIT_FOR_OPEN);
 784         if (IS_ERR(gss_auth->dentry[1])) {
 785                 err = PTR_ERR(gss_auth->dentry[1]);
 786                 goto err_put_mech;
 787         }
 788
 789         gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_dentry,
 790                                          gss_auth->mech->gm_name,
 791                                          clnt, &gss_upcall_ops_v0,
 792                                          RPC_PIPE_WAIT_FOR_OPEN);
 793         if (IS_ERR(gss_auth->dentry[0])) {
 794                 err = PTR_ERR(gss_auth->dentry[0]);
 795                 goto err_unlink_pipe_1;
 796         }
 797         err = rpcauth_init_credcache(auth);
 798         if (err)
 799                 goto err_unlink_pipe_0;
 800
 801         return auth;
 802 err_unlink_pipe_0:
 803         rpc_unlink(gss_auth->dentry[0]);
 804 err_unlink_pipe_1:
 805         rpc_unlink(gss_auth->dentry[1]);
 806 err_put_mech:
 807         gss_mech_put(gss_auth->mech);
 808 err_free:
 809         kfree(gss_auth);
 810 out_dec:
 811         module_put(THIS_MODULE);
 812         return ERR_PTR(err);
 813 }
 814
 815 static void
 816 gss_free(struct gss_auth *gss_auth)
 817 {
 818         rpc_unlink(gss_auth->dentry[1]);
 819         rpc_unlink(gss_auth->dentry[0]);
 820         gss_mech_put(gss_auth->mech);
 821
 822         kfree(gss_auth);
 823         module_put(THIS_MODULE);
 824 }
 825
 826 static void
 827 gss_free_callback(struct kref *kref)
 828 {
 829         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 830
 831         gss_free(gss_auth);
 832 }
 833
 834 static void
 835 gss_destroy(struct rpc_auth *auth)
 836 {
 837         struct gss_auth *gss_auth;
 838
 839         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 840                         auth, auth->au_flavor);
 841
 842         rpcauth_destroy_credcache(auth);
 843
 844         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 845         kref_put(&gss_auth->kref, gss_free_callback);
 846 }
 847
 848 /*
 849  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 850  * to the server with the GSS control procedure field set to
 851  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 852  * all RPCSEC_GSS state associated with that context.
 853  */
 854 static int
 855 gss_destroying_context(struct rpc_cred *cred)
 856 {
 857         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 858         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 859         struct rpc_task *task;
 860
 861         if (gss_cred->gc_ctx == NULL ||
 862             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 863                 return 0;
 864
 865         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 866         cred->cr_ops = &gss_nullops;
 867
 868         /* Take a reference to ensure the cred will be destroyed either
 869          * by the RPC call or by the put_rpccred() below */
 870         get_rpccred(cred);
 871
 872         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 873         if (!IS_ERR(task))
 874                 rpc_put_task(task);
 875
 876         put_rpccred(cred);
 877         return 1;
 878 }
 879
 880 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 881  * to create a new cred or context, so they check that things have been
 882  * allocated before freeing them. */
 883 static void
 884 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 885 {
 886         dprintk("RPC:       gss_free_ctx\n");
 887
 888         kfree(ctx->gc_wire_ctx.data);
 889         kfree(ctx);
 890 }
 891
 892 static void
 893 gss_free_ctx_callback(struct rcu_head *head)
 894 {
 895         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 896         gss_do_free_ctx(ctx);
 897 }
 898
 899 static void
 900 gss_free_ctx(struct gss_cl_ctx *ctx)
 901 {
 902         struct gss_ctx *gc_gss_ctx;
 903
 904         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 905         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 906         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 907         if (gc_gss_ctx)
 908                 gss_delete_sec_context(&gc_gss_ctx);
 909 }
 910
 911 static void
 912 gss_free_cred(struct gss_cred *gss_cred)
 913 {
 914         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 915         kfree(gss_cred);
 916 }
 917
 918 static void
 919 gss_free_cred_callback(struct rcu_head *head)
 920 {
 921         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 922         gss_free_cred(gss_cred);
 923 }
 924
 925 static void
 926 gss_destroy_nullcred(struct rpc_cred *cred)
 927 {
 928         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 929         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 930         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 931
 932         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 933         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 934         if (ctx)
 935                 gss_put_ctx(ctx);
 936         kref_put(&gss_auth->kref, gss_free_callback);
 937 }
 938
 939 static void
 940 gss_destroy_cred(struct rpc_cred *cred)
 941 {
 942
 943         if (gss_destroying_context(cred))
 944                 return;
 945         gss_destroy_nullcred(cred);
 946 }
 947
 948 /*
 949  * Lookup RPCSEC_GSS cred for the current process
 950  */
 951 static struct rpc_cred *
 952 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 953 {
 954         return rpcauth_lookup_credcache(auth, acred, flags);
 955 }
 956
 957 static struct rpc_cred *
 958 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 959 {
 960         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 961         struct gss_cred *cred = NULL;
 962         int err = -ENOMEM;
 963
 964         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 965                 acred->uid, auth->au_flavor);
 966
 967         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
 968                 goto out_err;
 969
 970         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 971         /*
 972          * Note: in order to force a call to call_refresh(), we deliberately
 973          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 974          */
 975         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 976         cred->gc_service = gss_auth->service;
 977         cred->gc_machine_cred = acred->machine_cred;
 978         kref_get(&gss_auth->kref);
 979         return &cred->gc_base;
 980
 981 out_err:
 982         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 983         return ERR_PTR(err);
 984 }
 985
 986 static int
 987 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 988 {
 989         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 990         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 991         int err;
 992
 993         do {
 994                 err = gss_create_upcall(gss_auth, gss_cred);
 995         } while (err == -EAGAIN);
 996         return err;
 997 }
 998
 999 static int
1000 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1001 {
1002         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1003
1004         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1005                 goto out;
1006         /* Don't match with creds that have expired. */
1007         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1008                 return 0;
1009         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1010                 return 0;
1011 out:
1012         if (acred->machine_cred != gss_cred->gc_machine_cred)
1013                 return 0;
1014         return (rc->cr_uid == acred->uid);
1015 }
1016
1017 /*
1018 * Marshal credentials.
1019 * Maybe we should keep a cached credential for performance reasons.
1020 */
1021 static __be32 *
1022 gss_marshal(struct rpc_task *task, __be32 *p)
1023 {
1024         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1025         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1026                                                  gc_base);
1027         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1028         __be32          *cred_len;
1029         struct rpc_rqst *req = task->tk_rqstp;
1030         u32             maj_stat = 0;
1031         struct xdr_netobj mic;
1032         struct kvec     iov;
1033         struct xdr_buf  verf_buf;
1034
1035         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
1036
1037         *p++ = htonl(RPC_AUTH_GSS);
1038         cred_len = p++;
1039
1040         spin_lock(&ctx->gc_seq_lock);
1041         req->rq_seqno = ctx->gc_seq++;
1042         spin_unlock(&ctx->gc_seq_lock);
1043
1044         *p++ = htonl((u32) RPC_GSS_VERSION);
1045         *p++ = htonl((u32) ctx->gc_proc);
1046         *p++ = htonl((u32) req->rq_seqno);
1047         *p++ = htonl((u32) gss_cred->gc_service);
1048         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1049         *cred_len = htonl((p - (cred_len + 1)) << 2);
1050
1051         /* We compute the checksum for the verifier over the xdr-encoded bytes
1052          * starting with the xid and ending at the end of the credential: */
1053         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
1054                                         req->rq_snd_buf.head[0].iov_base);
1055         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1056         xdr_buf_from_iov(&iov, &verf_buf);
1057
1058         /* set verifier flavor*/
1059         *p++ = htonl(RPC_AUTH_GSS);
1060
1061         mic.data = (u8 *)(p + 1);
1062         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1063         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1064                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1065         } else if (maj_stat != 0) {
1066                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1067                 goto out_put_ctx;
1068         }
1069         p = xdr_encode_opaque(p, NULL, mic.len);
1070         gss_put_ctx(ctx);
1071         return p;
1072 out_put_ctx:
1073         gss_put_ctx(ctx);
1074         return NULL;
1075 }
1076
1077 static int gss_renew_cred(struct rpc_task *task)
1078 {
1079         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
1080         struct gss_cred *gss_cred = container_of(oldcred,
1081                                                  struct gss_cred,
1082                                                  gc_base);
1083         struct rpc_auth *auth = oldcred->cr_auth;
1084         struct auth_cred acred = {
1085                 .uid = oldcred->cr_uid,
1086                 .machine_cred = gss_cred->gc_machine_cred,
1087         };
1088         struct rpc_cred *new;
1089
1090         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1091         if (IS_ERR(new))
1092                 return PTR_ERR(new);
1093         task->tk_msg.rpc_cred = new;
1094         put_rpccred(oldcred);
1095         return 0;
1096 }
1097
1098 /*
1099 * Refresh credentials. XXX - finish
1100 */
1101 static int
1102 gss_refresh(struct rpc_task *task)
1103 {
1104         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1105         int ret = 0;
1106
1107         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1108                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1109                 ret = gss_renew_cred(task);
1110                 if (ret < 0)
1111                         goto out;
1112                 cred = task->tk_msg.rpc_cred;
1113         }
1114
1115         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1116                 ret = gss_refresh_upcall(task);
1117 out:
1118         return ret;
1119 }
1120
1121 /* Dummy refresh routine: used only when destroying the context */
1122 static int
1123 gss_refresh_null(struct rpc_task *task)
1124 {
1125         return -EACCES;
1126 }
1127
1128 static __be32 *
1129 gss_validate(struct rpc_task *task, __be32 *p)
1130 {
1131         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1132         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1133         __be32          seq;
1134         struct kvec     iov;
1135         struct xdr_buf  verf_buf;
1136         struct xdr_netobj mic;
1137         u32             flav,len;
1138         u32             maj_stat;
1139
1140         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
1141
1142         flav = ntohl(*p++);
1143         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1144                 goto out_bad;
1145         if (flav != RPC_AUTH_GSS)
1146                 goto out_bad;
1147         seq = htonl(task->tk_rqstp->rq_seqno);
1148         iov.iov_base = &seq;
1149         iov.iov_len = sizeof(seq);
1150         xdr_buf_from_iov(&iov, &verf_buf);
1151         mic.data = (u8 *)p;
1152         mic.len = len;
1153
1154         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1155         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1156                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1157         if (maj_stat) {
1158                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1159                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1160                 goto out_bad;
1161         }
1162         /* We leave it to unwrap to calculate au_rslack. For now we just
1163          * calculate the length of the verifier: */
1164         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1165         gss_put_ctx(ctx);
1166         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1167                         task->tk_pid);
1168         return p + XDR_QUADLEN(len);
1169 out_bad:
1170         gss_put_ctx(ctx);
1171         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1172         return NULL;
1173 }
1174
1175 static inline int
1176 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1177                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1178 {
1179         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1180         struct xdr_buf  integ_buf;
1181         __be32          *integ_len = NULL;
1182         struct xdr_netobj mic;
1183         u32             offset;
1184         __be32          *q;
1185         struct kvec     *iov;
1186         u32             maj_stat = 0;
1187         int             status = -EIO;
1188
1189         integ_len = p++;
1190         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1191         *p++ = htonl(rqstp->rq_seqno);
1192
1193         status = encode(rqstp, p, obj);
1194         if (status)
1195                 return status;
1196
1197         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1198                                 offset, snd_buf->len - offset))
1199                 return status;
1200         *integ_len = htonl(integ_buf.len);
1201
1202         /* guess whether we're in the head or the tail: */
1203         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1204                 iov = snd_buf->tail;
1205         else
1206                 iov = snd_buf->head;
1207         p = iov->iov_base + iov->iov_len;
1208         mic.data = (u8 *)(p + 1);
1209
1210         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1211         status = -EIO; /* XXX? */
1212         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1213                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1214         else if (maj_stat)
1215                 return status;
1216         q = xdr_encode_opaque(p, NULL, mic.len);
1217
1218         offset = (u8 *)q - (u8 *)p;
1219         iov->iov_len += offset;
1220         snd_buf->len += offset;
1221         return 0;
1222 }
1223
1224 static void
1225 priv_release_snd_buf(struct rpc_rqst *rqstp)
1226 {
1227         int i;
1228
1229         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1230                 __free_page(rqstp->rq_enc_pages[i]);
1231         kfree(rqstp->rq_enc_pages);
1232 }
1233
1234 static int
1235 alloc_enc_pages(struct rpc_rqst *rqstp)
1236 {
1237         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1238         int first, last, i;
1239
1240         if (snd_buf->page_len == 0) {
1241                 rqstp->rq_enc_pages_num = 0;
1242                 return 0;
1243         }
1244
1245         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1246         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1247         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1248         rqstp->rq_enc_pages
1249                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1250                                 GFP_NOFS);
1251         if (!rqstp->rq_enc_pages)
1252                 goto out;
1253         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1254                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1255                 if (rqstp->rq_enc_pages[i] == NULL)
1256                         goto out_free;
1257         }
1258         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1259         return 0;
1260 out_free:
1261         for (i--; i >= 0; i--) {
1262                 __free_page(rqstp->rq_enc_pages[i]);
1263         }
1264 out:
1265         return -EAGAIN;
1266 }
1267
1268 static inline int
1269 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1270                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1271 {
1272         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1273         u32             offset;
1274         u32             maj_stat;
1275         int             status;
1276         __be32          *opaque_len;
1277         struct page     **inpages;
1278         int             first;
1279         int             pad;
1280         struct kvec     *iov;
1281         char            *tmp;
1282
1283         opaque_len = p++;
1284         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1285         *p++ = htonl(rqstp->rq_seqno);
1286
1287         status = encode(rqstp, p, obj);
1288         if (status)
1289                 return status;
1290
1291         status = alloc_enc_pages(rqstp);
1292         if (status)
1293                 return status;
1294         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1295         inpages = snd_buf->pages + first;
1296         snd_buf->pages = rqstp->rq_enc_pages;
1297         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1298         /* Give the tail its own page, in case we need extra space in the
1299          * head when wrapping: */
1300         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1301                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1302                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1303                 snd_buf->tail[0].iov_base = tmp;
1304         }
1305         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1306         /* RPC_SLACK_SPACE should prevent this ever happening: */
1307         BUG_ON(snd_buf->len > snd_buf->buflen);
1308         status = -EIO;
1309         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1310          * done anyway, so it's safe to put the request on the wire: */
1311         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1312                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1313         else if (maj_stat)
1314                 return status;
1315
1316         *opaque_len = htonl(snd_buf->len - offset);
1317         /* guess whether we're in the head or the tail: */
1318         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1319                 iov = snd_buf->tail;
1320         else
1321                 iov = snd_buf->head;
1322         p = iov->iov_base + iov->iov_len;
1323         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1324         memset(p, 0, pad);
1325         iov->iov_len += pad;
1326         snd_buf->len += pad;
1327
1328         return 0;
1329 }
1330
1331 static int
1332 gss_wrap_req(struct rpc_task *task,
1333              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1334 {
1335         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1336         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1337                         gc_base);
1338         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1339         int             status = -EIO;
1340
1341         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1342         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1343                 /* The spec seems a little ambiguous here, but I think that not
1344                  * wrapping context destruction requests makes the most sense.
1345                  */
1346                 status = encode(rqstp, p, obj);
1347                 goto out;
1348         }
1349         switch (gss_cred->gc_service) {
1350                 case RPC_GSS_SVC_NONE:
1351                         status = encode(rqstp, p, obj);
1352                         break;
1353                 case RPC_GSS_SVC_INTEGRITY:
1354                         status = gss_wrap_req_integ(cred, ctx, encode,
1355                                                                 rqstp, p, obj);
1356                         break;
1357                 case RPC_GSS_SVC_PRIVACY:
1358                         status = gss_wrap_req_priv(cred, ctx, encode,
1359                                         rqstp, p, obj);
1360                         break;
1361         }
1362 out:
1363         gss_put_ctx(ctx);
1364         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1365         return status;
1366 }
1367
1368 static inline int
1369 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1370                 struct rpc_rqst *rqstp, __be32 **p)
1371 {
1372         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1373         struct xdr_buf integ_buf;
1374         struct xdr_netobj mic;
1375         u32 data_offset, mic_offset;
1376         u32 integ_len;
1377         u32 maj_stat;
1378         int status = -EIO;
1379
1380         integ_len = ntohl(*(*p)++);
1381         if (integ_len & 3)
1382                 return status;
1383         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1384         mic_offset = integ_len + data_offset;
1385         if (mic_offset > rcv_buf->len)
1386                 return status;
1387         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1388                 return status;
1389
1390         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1391                                 mic_offset - data_offset))
1392                 return status;
1393
1394         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1395                 return status;
1396
1397         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1398         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1399                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1400         if (maj_stat != GSS_S_COMPLETE)
1401                 return status;
1402         return 0;
1403 }
1404
1405 static inline int
1406 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1407                 struct rpc_rqst *rqstp, __be32 **p)
1408 {
1409         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1410         u32 offset;
1411         u32 opaque_len;
1412         u32 maj_stat;
1413         int status = -EIO;
1414
1415         opaque_len = ntohl(*(*p)++);
1416         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1417         if (offset + opaque_len > rcv_buf->len)
1418                 return status;
1419         /* remove padding: */
1420         rcv_buf->len = offset + opaque_len;
1421
1422         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1423         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1424                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1425         if (maj_stat != GSS_S_COMPLETE)
1426                 return status;
1427         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1428                 return status;
1429
1430         return 0;
1431 }
1432
1433
1434 static int
1435 gss_unwrap_resp(struct rpc_task *task,
1436                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1437 {
1438         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1439         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1440                         gc_base);
1441         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1442         __be32          *savedp = p;
1443         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1444         int             savedlen = head->iov_len;
1445         int             status = -EIO;
1446
1447         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1448                 goto out_decode;
1449         switch (gss_cred->gc_service) {
1450                 case RPC_GSS_SVC_NONE:
1451                         break;
1452                 case RPC_GSS_SVC_INTEGRITY:
1453                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1454                         if (status)
1455                                 goto out;
1456                         break;
1457                 case RPC_GSS_SVC_PRIVACY:
1458                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1459                         if (status)
1460                                 goto out;
1461                         break;
1462         }
1463         /* take into account extra slack for integrity and privacy cases: */
1464         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1465                                                 + (savedlen - head->iov_len);
1466 out_decode:
1467         status = decode(rqstp, p, obj);
1468 out:
1469         gss_put_ctx(ctx);
1470         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1471                         status);
1472         return status;
1473 }
1474
1475 static const struct rpc_authops authgss_ops = {
1476         .owner          = THIS_MODULE,
1477         .au_flavor      = RPC_AUTH_GSS,
1478         .au_name        = "RPCSEC_GSS",
1479         .create         = gss_create,
1480         .destroy        = gss_destroy,
1481         .lookup_cred    = gss_lookup_cred,
1482         .crcreate       = gss_create_cred
1483 };
1484
1485 static const struct rpc_credops gss_credops = {
1486         .cr_name        = "AUTH_GSS",
1487         .crdestroy      = gss_destroy_cred,
1488         .cr_init        = gss_cred_init,
1489         .crbind         = rpcauth_generic_bind_cred,
1490         .crmatch        = gss_match,
1491         .crmarshal      = gss_marshal,
1492         .crrefresh      = gss_refresh,
1493         .crvalidate     = gss_validate,
1494         .crwrap_req     = gss_wrap_req,
1495         .crunwrap_resp  = gss_unwrap_resp,
1496 };
1497
1498 static const struct rpc_credops gss_nullops = {
1499         .cr_name        = "AUTH_GSS",
1500         .crdestroy      = gss_destroy_nullcred,
1501         .crbind         = rpcauth_generic_bind_cred,
1502         .crmatch        = gss_match,
1503         .crmarshal      = gss_marshal,
1504         .crrefresh      = gss_refresh_null,
1505         .crvalidate     = gss_validate,
1506         .crwrap_req     = gss_wrap_req,
1507         .crunwrap_resp  = gss_unwrap_resp,
1508 };
1509
1510 static struct rpc_pipe_ops gss_upcall_ops_v0 = {
1511         .upcall         = gss_pipe_upcall,
1512         .downcall       = gss_pipe_downcall,
1513         .destroy_msg    = gss_pipe_destroy_msg,
1514         .open_pipe      = gss_pipe_open_v0,
1515         .release_pipe   = gss_pipe_release,
1516 };
1517
1518 static struct rpc_pipe_ops gss_upcall_ops_v1 = {
1519         .upcall         = gss_pipe_upcall,
1520         .downcall       = gss_pipe_downcall,
1521         .destroy_msg    = gss_pipe_destroy_msg,
1522         .open_pipe      = gss_pipe_open_v1,
1523         .release_pipe   = gss_pipe_release,
1524 };
1525
1526 /*
1527  * Initialize RPCSEC_GSS module
1528  */
1529 static int __init init_rpcsec_gss(void)
1530 {
1531         int err = 0;
1532
1533         err = rpcauth_register(&authgss_ops);
1534         if (err)
1535                 goto out;
1536         err = gss_svc_init();
1537         if (err)
1538                 goto out_unregister;
1539         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1540         return 0;
1541 out_unregister:
1542         rpcauth_unregister(&authgss_ops);
1543 out:
1544         return err;
1545 }
1546
1547 static void __exit exit_rpcsec_gss(void)
1548 {
1549         gss_svc_shutdown();
1550         rpcauth_unregister(&authgss_ops);
1551         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1552 }
1553
1554 MODULE_LICENSE("GPL");
1555 module_init(init_rpcsec_gss)
1556 module_exit(exit_rpcsec_gss)