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