net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54
  55 static const struct rpc_authops authgss_ops;
  56
  57 static const struct rpc_credops gss_credops;
  58 static const struct rpc_credops gss_nullops;
  59
  60 #ifdef RPC_DEBUG
  61 # define RPCDBG_FACILITY        RPCDBG_AUTH
  62 #endif
  63
  64 #define GSS_CRED_SLACK          1024
  65 /* length of a krb5 verifier (48), plus data added before arguments when
  66  * using integrity (two 4-byte integers): */
  67 #define GSS_VERF_SLACK          100
  68
  69 struct gss_auth {
  70         struct kref kref;
  71         struct rpc_auth rpc_auth;
  72         struct gss_api_mech *mech;
  73         enum rpc_gss_svc service;
  74         struct rpc_clnt *client;
  75         struct dentry *dentry;
  76 };
  77
  78 static void gss_free_ctx(struct gss_cl_ctx *);
  79 static struct rpc_pipe_ops gss_upcall_ops;
  80
  81 static inline struct gss_cl_ctx *
  82 gss_get_ctx(struct gss_cl_ctx *ctx)
  83 {
  84         atomic_inc(&ctx->count);
  85         return ctx;
  86 }
  87
  88 static inline void
  89 gss_put_ctx(struct gss_cl_ctx *ctx)
  90 {
  91         if (atomic_dec_and_test(&ctx->count))
  92                 gss_free_ctx(ctx);
  93 }
  94
  95 /* gss_cred_set_ctx:
  96  * called by gss_upcall_callback and gss_create_upcall in order
  97  * to set the gss context. The actual exchange of an old context
  98  * and a new one is protected by the inode->i_lock.
  99  */
 100 static void
 101 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 102 {
 103         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 104
 105         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 106                 return;
 107         gss_get_ctx(ctx);
 108         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 109         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 110         smp_mb__before_clear_bit();
 111         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 112 }
 113
 114 static const void *
 115 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 116 {
 117         const void *q = (const void *)((const char *)p + len);
 118         if (unlikely(q > end || q < p))
 119                 return ERR_PTR(-EFAULT);
 120         memcpy(res, p, len);
 121         return q;
 122 }
 123
 124 static inline const void *
 125 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 126 {
 127         const void *q;
 128         unsigned int len;
 129
 130         p = simple_get_bytes(p, end, &len, sizeof(len));
 131         if (IS_ERR(p))
 132                 return p;
 133         q = (const void *)((const char *)p + len);
 134         if (unlikely(q > end || q < p))
 135                 return ERR_PTR(-EFAULT);
 136         dest->data = kmemdup(p, len, GFP_NOFS);
 137         if (unlikely(dest->data == NULL))
 138                 return ERR_PTR(-ENOMEM);
 139         dest->len = len;
 140         return q;
 141 }
 142
 143 static struct gss_cl_ctx *
 144 gss_cred_get_ctx(struct rpc_cred *cred)
 145 {
 146         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 147         struct gss_cl_ctx *ctx = NULL;
 148
 149         rcu_read_lock();
 150         if (gss_cred->gc_ctx)
 151                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 152         rcu_read_unlock();
 153         return ctx;
 154 }
 155
 156 static struct gss_cl_ctx *
 157 gss_alloc_context(void)
 158 {
 159         struct gss_cl_ctx *ctx;
 160
 161         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 162         if (ctx != NULL) {
 163                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 164                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 165                 spin_lock_init(&ctx->gc_seq_lock);
 166                 atomic_set(&ctx->count,1);
 167         }
 168         return ctx;
 169 }
 170
 171 #define GSSD_MIN_TIMEOUT (60 * 60)
 172 static const void *
 173 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 174 {
 175         const void *q;
 176         unsigned int seclen;
 177         unsigned int timeout;
 178         u32 window_size;
 179         int ret;
 180
 181         /* First unsigned int gives the lifetime (in seconds) of the cred */
 182         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 183         if (IS_ERR(p))
 184                 goto err;
 185         if (timeout == 0)
 186                 timeout = GSSD_MIN_TIMEOUT;
 187         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 188         /* Sequence number window. Determines the maximum number of simultaneous requests */
 189         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 190         if (IS_ERR(p))
 191                 goto err;
 192         ctx->gc_win = window_size;
 193         /* gssd signals an error by passing ctx->gc_win = 0: */
 194         if (ctx->gc_win == 0) {
 195                 /* in which case, p points to  an error code which we ignore */
 196                 p = ERR_PTR(-EACCES);
 197                 goto err;
 198         }
 199         /* copy the opaque wire context */
 200         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 201         if (IS_ERR(p))
 202                 goto err;
 203         /* import the opaque security context */
 204         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 205         if (IS_ERR(p))
 206                 goto err;
 207         q = (const void *)((const char *)p + seclen);
 208         if (unlikely(q > end || q < p)) {
 209                 p = ERR_PTR(-EFAULT);
 210                 goto err;
 211         }
 212         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 213         if (ret < 0) {
 214                 p = ERR_PTR(ret);
 215                 goto err;
 216         }
 217         return q;
 218 err:
 219         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 220         return p;
 221 }
 222
 223
 224 struct gss_upcall_msg {
 225         atomic_t count;
 226         uid_t   uid;
 227         struct rpc_pipe_msg msg;
 228         struct list_head list;
 229         struct gss_auth *auth;
 230         struct rpc_wait_queue rpc_waitqueue;
 231         wait_queue_head_t waitqueue;
 232         struct gss_cl_ctx *ctx;
 233 };
 234
 235 static void
 236 gss_release_msg(struct gss_upcall_msg *gss_msg)
 237 {
 238         if (!atomic_dec_and_test(&gss_msg->count))
 239                 return;
 240         BUG_ON(!list_empty(&gss_msg->list));
 241         if (gss_msg->ctx != NULL)
 242                 gss_put_ctx(gss_msg->ctx);
 243         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 244         kfree(gss_msg);
 245 }
 246
 247 static struct gss_upcall_msg *
 248 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 249 {
 250         struct gss_upcall_msg *pos;
 251         list_for_each_entry(pos, &rpci->in_downcall, list) {
 252                 if (pos->uid != uid)
 253                         continue;
 254                 atomic_inc(&pos->count);
 255                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 256                 return pos;
 257         }
 258         dprintk("RPC:       gss_find_upcall found nothing\n");
 259         return NULL;
 260 }
 261
 262 /* Try to add an upcall to the pipefs queue.
 263  * If an upcall owned by our uid already exists, then we return a reference
 264  * to that upcall instead of adding the new upcall.
 265  */
 266 static inline struct gss_upcall_msg *
 267 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 268 {
 269         struct inode *inode = gss_auth->dentry->d_inode;
 270         struct rpc_inode *rpci = RPC_I(inode);
 271         struct gss_upcall_msg *old;
 272
 273         spin_lock(&inode->i_lock);
 274         old = __gss_find_upcall(rpci, gss_msg->uid);
 275         if (old == NULL) {
 276                 atomic_inc(&gss_msg->count);
 277                 list_add(&gss_msg->list, &rpci->in_downcall);
 278         } else
 279                 gss_msg = old;
 280         spin_unlock(&inode->i_lock);
 281         return gss_msg;
 282 }
 283
 284 static void
 285 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 286 {
 287         list_del_init(&gss_msg->list);
 288         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 289         wake_up_all(&gss_msg->waitqueue);
 290         atomic_dec(&gss_msg->count);
 291 }
 292
 293 static void
 294 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 295 {
 296         struct gss_auth *gss_auth = gss_msg->auth;
 297         struct inode *inode = gss_auth->dentry->d_inode;
 298
 299         if (list_empty(&gss_msg->list))
 300                 return;
 301         spin_lock(&inode->i_lock);
 302         if (!list_empty(&gss_msg->list))
 303                 __gss_unhash_msg(gss_msg);
 304         spin_unlock(&inode->i_lock);
 305 }
 306
 307 static void
 308 gss_upcall_callback(struct rpc_task *task)
 309 {
 310         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 311                         struct gss_cred, gc_base);
 312         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 313         struct inode *inode = gss_msg->auth->dentry->d_inode;
 314
 315         spin_lock(&inode->i_lock);
 316         if (gss_msg->ctx)
 317                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 318         else
 319                 task->tk_status = gss_msg->msg.errno;
 320         gss_cred->gc_upcall = NULL;
 321         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 322         spin_unlock(&inode->i_lock);
 323         gss_release_msg(gss_msg);
 324 }
 325
 326 static inline struct gss_upcall_msg *
 327 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 328 {
 329         struct gss_upcall_msg *gss_msg;
 330
 331         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 332         if (gss_msg != NULL) {
 333                 INIT_LIST_HEAD(&gss_msg->list);
 334                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 335                 init_waitqueue_head(&gss_msg->waitqueue);
 336                 atomic_set(&gss_msg->count, 1);
 337                 gss_msg->msg.data = &gss_msg->uid;
 338                 gss_msg->msg.len = sizeof(gss_msg->uid);
 339                 gss_msg->uid = uid;
 340                 gss_msg->auth = gss_auth;
 341         }
 342         return gss_msg;
 343 }
 344
 345 static struct gss_upcall_msg *
 346 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 347 {
 348         struct gss_cred *gss_cred = container_of(cred,
 349                         struct gss_cred, gc_base);
 350         struct gss_upcall_msg *gss_new, *gss_msg;
 351         uid_t uid = cred->cr_uid;
 352
 353         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
 354         if (gss_cred->gc_machine_cred != 0)
 355                 uid = 0;
 356
 357         gss_new = gss_alloc_msg(gss_auth, uid);
 358         if (gss_new == NULL)
 359                 return ERR_PTR(-ENOMEM);
 360         gss_msg = gss_add_msg(gss_auth, gss_new);
 361         if (gss_msg == gss_new) {
 362                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 363                 if (res) {
 364                         gss_unhash_msg(gss_new);
 365                         gss_msg = ERR_PTR(res);
 366                 }
 367         } else
 368                 gss_release_msg(gss_new);
 369         return gss_msg;
 370 }
 371
 372 static inline int
 373 gss_refresh_upcall(struct rpc_task *task)
 374 {
 375         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 376         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 377                         struct gss_auth, rpc_auth);
 378         struct gss_cred *gss_cred = container_of(cred,
 379                         struct gss_cred, gc_base);
 380         struct gss_upcall_msg *gss_msg;
 381         struct inode *inode = gss_auth->dentry->d_inode;
 382         int err = 0;
 383
 384         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 385                                                                 cred->cr_uid);
 386         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 387         if (IS_ERR(gss_msg)) {
 388                 err = PTR_ERR(gss_msg);
 389                 goto out;
 390         }
 391         spin_lock(&inode->i_lock);
 392         if (gss_cred->gc_upcall != NULL)
 393                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 394         else if (gss_msg->ctx != NULL) {
 395                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 396                 gss_cred->gc_upcall = NULL;
 397                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 398         } else if (gss_msg->msg.errno >= 0) {
 399                 task->tk_timeout = 0;
 400                 gss_cred->gc_upcall = gss_msg;
 401                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 402                 atomic_inc(&gss_msg->count);
 403                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 404         } else
 405                 err = gss_msg->msg.errno;
 406         spin_unlock(&inode->i_lock);
 407         gss_release_msg(gss_msg);
 408 out:
 409         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 410                         task->tk_pid, cred->cr_uid, err);
 411         return err;
 412 }
 413
 414 static inline int
 415 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 416 {
 417         struct inode *inode = gss_auth->dentry->d_inode;
 418         struct rpc_cred *cred = &gss_cred->gc_base;
 419         struct gss_upcall_msg *gss_msg;
 420         DEFINE_WAIT(wait);
 421         int err = 0;
 422
 423         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 424         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 425         if (IS_ERR(gss_msg)) {
 426                 err = PTR_ERR(gss_msg);
 427                 goto out;
 428         }
 429         for (;;) {
 430                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 431                 spin_lock(&inode->i_lock);
 432                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 433                         break;
 434                 }
 435                 spin_unlock(&inode->i_lock);
 436                 if (signalled()) {
 437                         err = -ERESTARTSYS;
 438                         goto out_intr;
 439                 }
 440                 schedule();
 441         }
 442         if (gss_msg->ctx)
 443                 gss_cred_set_ctx(cred, gss_msg->ctx);
 444         else
 445                 err = gss_msg->msg.errno;
 446         spin_unlock(&inode->i_lock);
 447 out_intr:
 448         finish_wait(&gss_msg->waitqueue, &wait);
 449         gss_release_msg(gss_msg);
 450 out:
 451         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 452                         cred->cr_uid, err);
 453         return err;
 454 }
 455
 456 static ssize_t
 457 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 458                 char __user *dst, size_t buflen)
 459 {
 460         char *data = (char *)msg->data + msg->copied;
 461         size_t mlen = min(msg->len, buflen);
 462         unsigned long left;
 463
 464         left = copy_to_user(dst, data, mlen);
 465         if (left == mlen) {
 466                 msg->errno = -EFAULT;
 467                 return -EFAULT;
 468         }
 469
 470         mlen -= left;
 471         msg->copied += mlen;
 472         msg->errno = 0;
 473         return mlen;
 474 }
 475
 476 #define MSG_BUF_MAXSIZE 1024
 477
 478 static ssize_t
 479 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 480 {
 481         const void *p, *end;
 482         void *buf;
 483         struct gss_upcall_msg *gss_msg;
 484         struct inode *inode = filp->f_path.dentry->d_inode;
 485         struct gss_cl_ctx *ctx;
 486         uid_t uid;
 487         ssize_t err = -EFBIG;
 488
 489         if (mlen > MSG_BUF_MAXSIZE)
 490                 goto out;
 491         err = -ENOMEM;
 492         buf = kmalloc(mlen, GFP_NOFS);
 493         if (!buf)
 494                 goto out;
 495
 496         err = -EFAULT;
 497         if (copy_from_user(buf, src, mlen))
 498                 goto err;
 499
 500         end = (const void *)((char *)buf + mlen);
 501         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 502         if (IS_ERR(p)) {
 503                 err = PTR_ERR(p);
 504                 goto err;
 505         }
 506
 507         err = -ENOMEM;
 508         ctx = gss_alloc_context();
 509         if (ctx == NULL)
 510                 goto err;
 511
 512         err = -ENOENT;
 513         /* Find a matching upcall */
 514         spin_lock(&inode->i_lock);
 515         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 516         if (gss_msg == NULL) {
 517                 spin_unlock(&inode->i_lock);
 518                 goto err_put_ctx;
 519         }
 520         list_del_init(&gss_msg->list);
 521         spin_unlock(&inode->i_lock);
 522
 523         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 524         if (IS_ERR(p)) {
 525                 err = PTR_ERR(p);
 526                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 527                 goto err_release_msg;
 528         }
 529         gss_msg->ctx = gss_get_ctx(ctx);
 530         err = mlen;
 531
 532 err_release_msg:
 533         spin_lock(&inode->i_lock);
 534         __gss_unhash_msg(gss_msg);
 535         spin_unlock(&inode->i_lock);
 536         gss_release_msg(gss_msg);
 537 err_put_ctx:
 538         gss_put_ctx(ctx);
 539 err:
 540         kfree(buf);
 541 out:
 542         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 543         return err;
 544 }
 545
 546 static void
 547 gss_pipe_release(struct inode *inode)
 548 {
 549         struct rpc_inode *rpci = RPC_I(inode);
 550         struct gss_upcall_msg *gss_msg;
 551
 552         spin_lock(&inode->i_lock);
 553         while (!list_empty(&rpci->in_downcall)) {
 554
 555                 gss_msg = list_entry(rpci->in_downcall.next,
 556                                 struct gss_upcall_msg, list);
 557                 gss_msg->msg.errno = -EPIPE;
 558                 atomic_inc(&gss_msg->count);
 559                 __gss_unhash_msg(gss_msg);
 560                 spin_unlock(&inode->i_lock);
 561                 gss_release_msg(gss_msg);
 562                 spin_lock(&inode->i_lock);
 563         }
 564         spin_unlock(&inode->i_lock);
 565 }
 566
 567 static void
 568 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 569 {
 570         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 571         static unsigned long ratelimit;
 572
 573         if (msg->errno < 0) {
 574                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 575                                 gss_msg);
 576                 atomic_inc(&gss_msg->count);
 577                 gss_unhash_msg(gss_msg);
 578                 if (msg->errno == -ETIMEDOUT) {
 579                         unsigned long now = jiffies;
 580                         if (time_after(now, ratelimit)) {
 581                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 582                                                     "Please check user daemon is running!\n");
 583                                 ratelimit = now + 15*HZ;
 584                         }
 585                 }
 586                 gss_release_msg(gss_msg);
 587         }
 588 }
 589
 590 /*
 591  * NOTE: we have the opportunity to use different
 592  * parameters based on the input flavor (which must be a pseudoflavor)
 593  */
 594 static struct rpc_auth *
 595 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 596 {
 597         struct gss_auth *gss_auth;
 598         struct rpc_auth * auth;
 599         int err = -ENOMEM; /* XXX? */
 600
 601         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 602
 603         if (!try_module_get(THIS_MODULE))
 604                 return ERR_PTR(err);
 605         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 606                 goto out_dec;
 607         gss_auth->client = clnt;
 608         err = -EINVAL;
 609         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 610         if (!gss_auth->mech) {
 611                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 612                                 __func__, flavor);
 613                 goto err_free;
 614         }
 615         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 616         if (gss_auth->service == 0)
 617                 goto err_put_mech;
 618         auth = &gss_auth->rpc_auth;
 619         auth->au_cslack = GSS_CRED_SLACK >> 2;
 620         auth->au_rslack = GSS_VERF_SLACK >> 2;
 621         auth->au_ops = &authgss_ops;
 622         auth->au_flavor = flavor;
 623         atomic_set(&auth->au_count, 1);
 624         kref_init(&gss_auth->kref);
 625
 626         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 627                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 628         if (IS_ERR(gss_auth->dentry)) {
 629                 err = PTR_ERR(gss_auth->dentry);
 630                 goto err_put_mech;
 631         }
 632
 633         err = rpcauth_init_credcache(auth);
 634         if (err)
 635                 goto err_unlink_pipe;
 636
 637         return auth;
 638 err_unlink_pipe:
 639         rpc_unlink(gss_auth->dentry);
 640 err_put_mech:
 641         gss_mech_put(gss_auth->mech);
 642 err_free:
 643         kfree(gss_auth);
 644 out_dec:
 645         module_put(THIS_MODULE);
 646         return ERR_PTR(err);
 647 }
 648
 649 static void
 650 gss_free(struct gss_auth *gss_auth)
 651 {
 652         rpc_unlink(gss_auth->dentry);
 653         gss_mech_put(gss_auth->mech);
 654
 655         kfree(gss_auth);
 656         module_put(THIS_MODULE);
 657 }
 658
 659 static void
 660 gss_free_callback(struct kref *kref)
 661 {
 662         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 663
 664         gss_free(gss_auth);
 665 }
 666
 667 static void
 668 gss_destroy(struct rpc_auth *auth)
 669 {
 670         struct gss_auth *gss_auth;
 671
 672         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 673                         auth, auth->au_flavor);
 674
 675         rpcauth_destroy_credcache(auth);
 676
 677         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 678         kref_put(&gss_auth->kref, gss_free_callback);
 679 }
 680
 681 /*
 682  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 683  * to the server with the GSS control procedure field set to
 684  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 685  * all RPCSEC_GSS state associated with that context.
 686  */
 687 static int
 688 gss_destroying_context(struct rpc_cred *cred)
 689 {
 690         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 691         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 692         struct rpc_task *task;
 693
 694         if (gss_cred->gc_ctx == NULL ||
 695             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 696                 return 0;
 697
 698         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 699         cred->cr_ops = &gss_nullops;
 700
 701         /* Take a reference to ensure the cred will be destroyed either
 702          * by the RPC call or by the put_rpccred() below */
 703         get_rpccred(cred);
 704
 705         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 706         if (!IS_ERR(task))
 707                 rpc_put_task(task);
 708
 709         put_rpccred(cred);
 710         return 1;
 711 }
 712
 713 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 714  * to create a new cred or context, so they check that things have been
 715  * allocated before freeing them. */
 716 static void
 717 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 718 {
 719         dprintk("RPC:       gss_free_ctx\n");
 720
 721         kfree(ctx->gc_wire_ctx.data);
 722         kfree(ctx);
 723 }
 724
 725 static void
 726 gss_free_ctx_callback(struct rcu_head *head)
 727 {
 728         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 729         gss_do_free_ctx(ctx);
 730 }
 731
 732 static void
 733 gss_free_ctx(struct gss_cl_ctx *ctx)
 734 {
 735         struct gss_ctx *gc_gss_ctx;
 736
 737         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 738         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 739         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 740         if (gc_gss_ctx)
 741                 gss_delete_sec_context(&gc_gss_ctx);
 742 }
 743
 744 static void
 745 gss_free_cred(struct gss_cred *gss_cred)
 746 {
 747         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 748         kfree(gss_cred);
 749 }
 750
 751 static void
 752 gss_free_cred_callback(struct rcu_head *head)
 753 {
 754         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 755         gss_free_cred(gss_cred);
 756 }
 757
 758 static void
 759 gss_destroy_nullcred(struct rpc_cred *cred)
 760 {
 761         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 762         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 763         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 764
 765         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 766         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 767         if (ctx)
 768                 gss_put_ctx(ctx);
 769         kref_put(&gss_auth->kref, gss_free_callback);
 770 }
 771
 772 static void
 773 gss_destroy_cred(struct rpc_cred *cred)
 774 {
 775
 776         if (gss_destroying_context(cred))
 777                 return;
 778         gss_destroy_nullcred(cred);
 779 }
 780
 781 /*
 782  * Lookup RPCSEC_GSS cred for the current process
 783  */
 784 static struct rpc_cred *
 785 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 786 {
 787         return rpcauth_lookup_credcache(auth, acred, flags);
 788 }
 789
 790 static struct rpc_cred *
 791 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 792 {
 793         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 794         struct gss_cred *cred = NULL;
 795         int err = -ENOMEM;
 796
 797         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 798                 acred->uid, auth->au_flavor);
 799
 800         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
 801                 goto out_err;
 802
 803         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 804         /*
 805          * Note: in order to force a call to call_refresh(), we deliberately
 806          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 807          */
 808         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 809         cred->gc_service = gss_auth->service;
 810         cred->gc_machine_cred = acred->machine_cred;
 811         kref_get(&gss_auth->kref);
 812         return &cred->gc_base;
 813
 814 out_err:
 815         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 816         return ERR_PTR(err);
 817 }
 818
 819 static int
 820 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 821 {
 822         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 823         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 824         int err;
 825
 826         do {
 827                 err = gss_create_upcall(gss_auth, gss_cred);
 828         } while (err == -EAGAIN);
 829         return err;
 830 }
 831
 832 static int
 833 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 834 {
 835         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 836
 837         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 838                 goto out;
 839         /* Don't match with creds that have expired. */
 840         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 841                 return 0;
 842         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
 843                 return 0;
 844 out:
 845         if (acred->machine_cred != gss_cred->gc_machine_cred)
 846                 return 0;
 847         return (rc->cr_uid == acred->uid);
 848 }
 849
 850 /*
 851 * Marshal credentials.
 852 * Maybe we should keep a cached credential for performance reasons.
 853 */
 854 static __be32 *
 855 gss_marshal(struct rpc_task *task, __be32 *p)
 856 {
 857         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 858         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 859                                                  gc_base);
 860         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 861         __be32          *cred_len;
 862         struct rpc_rqst *req = task->tk_rqstp;
 863         u32             maj_stat = 0;
 864         struct xdr_netobj mic;
 865         struct kvec     iov;
 866         struct xdr_buf  verf_buf;
 867
 868         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 869
 870         *p++ = htonl(RPC_AUTH_GSS);
 871         cred_len = p++;
 872
 873         spin_lock(&ctx->gc_seq_lock);
 874         req->rq_seqno = ctx->gc_seq++;
 875         spin_unlock(&ctx->gc_seq_lock);
 876
 877         *p++ = htonl((u32) RPC_GSS_VERSION);
 878         *p++ = htonl((u32) ctx->gc_proc);
 879         *p++ = htonl((u32) req->rq_seqno);
 880         *p++ = htonl((u32) gss_cred->gc_service);
 881         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 882         *cred_len = htonl((p - (cred_len + 1)) << 2);
 883
 884         /* We compute the checksum for the verifier over the xdr-encoded bytes
 885          * starting with the xid and ending at the end of the credential: */
 886         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 887                                         req->rq_snd_buf.head[0].iov_base);
 888         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 889         xdr_buf_from_iov(&iov, &verf_buf);
 890
 891         /* set verifier flavor*/
 892         *p++ = htonl(RPC_AUTH_GSS);
 893
 894         mic.data = (u8 *)(p + 1);
 895         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 896         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 897                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 898         } else if (maj_stat != 0) {
 899                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 900                 goto out_put_ctx;
 901         }
 902         p = xdr_encode_opaque(p, NULL, mic.len);
 903         gss_put_ctx(ctx);
 904         return p;
 905 out_put_ctx:
 906         gss_put_ctx(ctx);
 907         return NULL;
 908 }
 909
 910 static int gss_renew_cred(struct rpc_task *task)
 911 {
 912         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
 913         struct gss_cred *gss_cred = container_of(oldcred,
 914                                                  struct gss_cred,
 915                                                  gc_base);
 916         struct rpc_auth *auth = oldcred->cr_auth;
 917         struct auth_cred acred = {
 918                 .uid = oldcred->cr_uid,
 919                 .machine_cred = gss_cred->gc_machine_cred,
 920         };
 921         struct rpc_cred *new;
 922
 923         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
 924         if (IS_ERR(new))
 925                 return PTR_ERR(new);
 926         task->tk_msg.rpc_cred = new;
 927         put_rpccred(oldcred);
 928         return 0;
 929 }
 930
 931 /*
 932 * Refresh credentials. XXX - finish
 933 */
 934 static int
 935 gss_refresh(struct rpc_task *task)
 936 {
 937         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 938         int ret = 0;
 939
 940         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 941                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
 942                 ret = gss_renew_cred(task);
 943                 if (ret < 0)
 944                         goto out;
 945                 cred = task->tk_msg.rpc_cred;
 946         }
 947
 948         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 949                 ret = gss_refresh_upcall(task);
 950 out:
 951         return ret;
 952 }
 953
 954 /* Dummy refresh routine: used only when destroying the context */
 955 static int
 956 gss_refresh_null(struct rpc_task *task)
 957 {
 958         return -EACCES;
 959 }
 960
 961 static __be32 *
 962 gss_validate(struct rpc_task *task, __be32 *p)
 963 {
 964         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 965         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 966         __be32          seq;
 967         struct kvec     iov;
 968         struct xdr_buf  verf_buf;
 969         struct xdr_netobj mic;
 970         u32             flav,len;
 971         u32             maj_stat;
 972
 973         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 974
 975         flav = ntohl(*p++);
 976         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 977                 goto out_bad;
 978         if (flav != RPC_AUTH_GSS)
 979                 goto out_bad;
 980         seq = htonl(task->tk_rqstp->rq_seqno);
 981         iov.iov_base = &seq;
 982         iov.iov_len = sizeof(seq);
 983         xdr_buf_from_iov(&iov, &verf_buf);
 984         mic.data = (u8 *)p;
 985         mic.len = len;
 986
 987         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 988         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 989                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 990         if (maj_stat) {
 991                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
 992                                 "error 0x%08x\n", task->tk_pid, maj_stat);
 993                 goto out_bad;
 994         }
 995         /* We leave it to unwrap to calculate au_rslack. For now we just
 996          * calculate the length of the verifier: */
 997         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
 998         gss_put_ctx(ctx);
 999         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1000                         task->tk_pid);
1001         return p + XDR_QUADLEN(len);
1002 out_bad:
1003         gss_put_ctx(ctx);
1004         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1005         return NULL;
1006 }
1007
1008 static inline int
1009 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1010                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1011 {
1012         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1013         struct xdr_buf  integ_buf;
1014         __be32          *integ_len = NULL;
1015         struct xdr_netobj mic;
1016         u32             offset;
1017         __be32          *q;
1018         struct kvec     *iov;
1019         u32             maj_stat = 0;
1020         int             status = -EIO;
1021
1022         integ_len = p++;
1023         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1024         *p++ = htonl(rqstp->rq_seqno);
1025
1026         status = encode(rqstp, p, obj);
1027         if (status)
1028                 return status;
1029
1030         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1031                                 offset, snd_buf->len - offset))
1032                 return status;
1033         *integ_len = htonl(integ_buf.len);
1034
1035         /* guess whether we're in the head or the tail: */
1036         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1037                 iov = snd_buf->tail;
1038         else
1039                 iov = snd_buf->head;
1040         p = iov->iov_base + iov->iov_len;
1041         mic.data = (u8 *)(p + 1);
1042
1043         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1044         status = -EIO; /* XXX? */
1045         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1046                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1047         else if (maj_stat)
1048                 return status;
1049         q = xdr_encode_opaque(p, NULL, mic.len);
1050
1051         offset = (u8 *)q - (u8 *)p;
1052         iov->iov_len += offset;
1053         snd_buf->len += offset;
1054         return 0;
1055 }
1056
1057 static void
1058 priv_release_snd_buf(struct rpc_rqst *rqstp)
1059 {
1060         int i;
1061
1062         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1063                 __free_page(rqstp->rq_enc_pages[i]);
1064         kfree(rqstp->rq_enc_pages);
1065 }
1066
1067 static int
1068 alloc_enc_pages(struct rpc_rqst *rqstp)
1069 {
1070         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1071         int first, last, i;
1072
1073         if (snd_buf->page_len == 0) {
1074                 rqstp->rq_enc_pages_num = 0;
1075                 return 0;
1076         }
1077
1078         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1079         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1080         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1081         rqstp->rq_enc_pages
1082                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1083                                 GFP_NOFS);
1084         if (!rqstp->rq_enc_pages)
1085                 goto out;
1086         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1087                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1088                 if (rqstp->rq_enc_pages[i] == NULL)
1089                         goto out_free;
1090         }
1091         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1092         return 0;
1093 out_free:
1094         for (i--; i >= 0; i--) {
1095                 __free_page(rqstp->rq_enc_pages[i]);
1096         }
1097 out:
1098         return -EAGAIN;
1099 }
1100
1101 static inline int
1102 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1103                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1104 {
1105         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1106         u32             offset;
1107         u32             maj_stat;
1108         int             status;
1109         __be32          *opaque_len;
1110         struct page     **inpages;
1111         int             first;
1112         int             pad;
1113         struct kvec     *iov;
1114         char            *tmp;
1115
1116         opaque_len = p++;
1117         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1118         *p++ = htonl(rqstp->rq_seqno);
1119
1120         status = encode(rqstp, p, obj);
1121         if (status)
1122                 return status;
1123
1124         status = alloc_enc_pages(rqstp);
1125         if (status)
1126                 return status;
1127         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1128         inpages = snd_buf->pages + first;
1129         snd_buf->pages = rqstp->rq_enc_pages;
1130         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1131         /* Give the tail its own page, in case we need extra space in the
1132          * head when wrapping: */
1133         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1134                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1135                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1136                 snd_buf->tail[0].iov_base = tmp;
1137         }
1138         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1139         /* RPC_SLACK_SPACE should prevent this ever happening: */
1140         BUG_ON(snd_buf->len > snd_buf->buflen);
1141         status = -EIO;
1142         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1143          * done anyway, so it's safe to put the request on the wire: */
1144         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1145                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1146         else if (maj_stat)
1147                 return status;
1148
1149         *opaque_len = htonl(snd_buf->len - offset);
1150         /* guess whether we're in the head or the tail: */
1151         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1152                 iov = snd_buf->tail;
1153         else
1154                 iov = snd_buf->head;
1155         p = iov->iov_base + iov->iov_len;
1156         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1157         memset(p, 0, pad);
1158         iov->iov_len += pad;
1159         snd_buf->len += pad;
1160
1161         return 0;
1162 }
1163
1164 static int
1165 gss_wrap_req(struct rpc_task *task,
1166              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1167 {
1168         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1169         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1170                         gc_base);
1171         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1172         int             status = -EIO;
1173
1174         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1175         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1176                 /* The spec seems a little ambiguous here, but I think that not
1177                  * wrapping context destruction requests makes the most sense.
1178                  */
1179                 status = encode(rqstp, p, obj);
1180                 goto out;
1181         }
1182         switch (gss_cred->gc_service) {
1183                 case RPC_GSS_SVC_NONE:
1184                         status = encode(rqstp, p, obj);
1185                         break;
1186                 case RPC_GSS_SVC_INTEGRITY:
1187                         status = gss_wrap_req_integ(cred, ctx, encode,
1188                                                                 rqstp, p, obj);
1189                         break;
1190                 case RPC_GSS_SVC_PRIVACY:
1191                         status = gss_wrap_req_priv(cred, ctx, encode,
1192                                         rqstp, p, obj);
1193                         break;
1194         }
1195 out:
1196         gss_put_ctx(ctx);
1197         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1198         return status;
1199 }
1200
1201 static inline int
1202 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1203                 struct rpc_rqst *rqstp, __be32 **p)
1204 {
1205         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1206         struct xdr_buf integ_buf;
1207         struct xdr_netobj mic;
1208         u32 data_offset, mic_offset;
1209         u32 integ_len;
1210         u32 maj_stat;
1211         int status = -EIO;
1212
1213         integ_len = ntohl(*(*p)++);
1214         if (integ_len & 3)
1215                 return status;
1216         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1217         mic_offset = integ_len + data_offset;
1218         if (mic_offset > rcv_buf->len)
1219                 return status;
1220         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1221                 return status;
1222
1223         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1224                                 mic_offset - data_offset))
1225                 return status;
1226
1227         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1228                 return status;
1229
1230         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1231         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1232                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1233         if (maj_stat != GSS_S_COMPLETE)
1234                 return status;
1235         return 0;
1236 }
1237
1238 static inline int
1239 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1240                 struct rpc_rqst *rqstp, __be32 **p)
1241 {
1242         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1243         u32 offset;
1244         u32 opaque_len;
1245         u32 maj_stat;
1246         int status = -EIO;
1247
1248         opaque_len = ntohl(*(*p)++);
1249         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1250         if (offset + opaque_len > rcv_buf->len)
1251                 return status;
1252         /* remove padding: */
1253         rcv_buf->len = offset + opaque_len;
1254
1255         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1256         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1257                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1258         if (maj_stat != GSS_S_COMPLETE)
1259                 return status;
1260         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1261                 return status;
1262
1263         return 0;
1264 }
1265
1266
1267 static int
1268 gss_unwrap_resp(struct rpc_task *task,
1269                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1270 {
1271         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1272         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1273                         gc_base);
1274         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1275         __be32          *savedp = p;
1276         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1277         int             savedlen = head->iov_len;
1278         int             status = -EIO;
1279
1280         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1281                 goto out_decode;
1282         switch (gss_cred->gc_service) {
1283                 case RPC_GSS_SVC_NONE:
1284                         break;
1285                 case RPC_GSS_SVC_INTEGRITY:
1286                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1287                         if (status)
1288                                 goto out;
1289                         break;
1290                 case RPC_GSS_SVC_PRIVACY:
1291                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1292                         if (status)
1293                                 goto out;
1294                         break;
1295         }
1296         /* take into account extra slack for integrity and privacy cases: */
1297         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1298                                                 + (savedlen - head->iov_len);
1299 out_decode:
1300         status = decode(rqstp, p, obj);
1301 out:
1302         gss_put_ctx(ctx);
1303         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1304                         status);
1305         return status;
1306 }
1307
1308 static const struct rpc_authops authgss_ops = {
1309         .owner          = THIS_MODULE,
1310         .au_flavor      = RPC_AUTH_GSS,
1311         .au_name        = "RPCSEC_GSS",
1312         .create         = gss_create,
1313         .destroy        = gss_destroy,
1314         .lookup_cred    = gss_lookup_cred,
1315         .crcreate       = gss_create_cred
1316 };
1317
1318 static const struct rpc_credops gss_credops = {
1319         .cr_name        = "AUTH_GSS",
1320         .crdestroy      = gss_destroy_cred,
1321         .cr_init        = gss_cred_init,
1322         .crbind         = rpcauth_generic_bind_cred,
1323         .crmatch        = gss_match,
1324         .crmarshal      = gss_marshal,
1325         .crrefresh      = gss_refresh,
1326         .crvalidate     = gss_validate,
1327         .crwrap_req     = gss_wrap_req,
1328         .crunwrap_resp  = gss_unwrap_resp,
1329 };
1330
1331 static const struct rpc_credops gss_nullops = {
1332         .cr_name        = "AUTH_GSS",
1333         .crdestroy      = gss_destroy_nullcred,
1334         .crbind         = rpcauth_generic_bind_cred,
1335         .crmatch        = gss_match,
1336         .crmarshal      = gss_marshal,
1337         .crrefresh      = gss_refresh_null,
1338         .crvalidate     = gss_validate,
1339         .crwrap_req     = gss_wrap_req,
1340         .crunwrap_resp  = gss_unwrap_resp,
1341 };
1342
1343 static struct rpc_pipe_ops gss_upcall_ops = {
1344         .upcall         = gss_pipe_upcall,
1345         .downcall       = gss_pipe_downcall,
1346         .destroy_msg    = gss_pipe_destroy_msg,
1347         .release_pipe   = gss_pipe_release,
1348 };
1349
1350 /*
1351  * Initialize RPCSEC_GSS module
1352  */
1353 static int __init init_rpcsec_gss(void)
1354 {
1355         int err = 0;
1356
1357         err = rpcauth_register(&authgss_ops);
1358         if (err)
1359                 goto out;
1360         err = gss_svc_init();
1361         if (err)
1362                 goto out_unregister;
1363         return 0;
1364 out_unregister:
1365         rpcauth_unregister(&authgss_ops);
1366 out:
1367         return err;
1368 }
1369
1370 static void __exit exit_rpcsec_gss(void)
1371 {
1372         gss_svc_shutdown();
1373         rpcauth_unregister(&authgss_ops);
1374 }
1375
1376 MODULE_LICENSE("GPL");
1377 module_init(init_rpcsec_gss)
1378 module_exit(exit_rpcsec_gss)