git.oblomov.eu Git - linux-2.6/blob - 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 NFS_NGROUPS     16
  65
  66 #define GSS_CRED_SLACK          1024            /* XXX: unused */
  67 /* length of a krb5 verifier (48), plus data added before arguments when
  68  * using integrity (two 4-byte integers): */
  69 #define GSS_VERF_SLACK          100
  70
  71 /* XXX this define must match the gssd define
  72 * as it is passed to gssd to signal the use of
  73 * machine creds should be part of the shared rpc interface */
  74
  75 #define CA_RUN_AS_MACHINE  0x00000200
  76
  77 /* dump the buffer in `emacs-hexl' style */
  78 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
  79
  80 struct gss_auth {
  81         struct kref kref;
  82         struct rpc_auth rpc_auth;
  83         struct gss_api_mech *mech;
  84         enum rpc_gss_svc service;
  85         struct rpc_clnt *client;
  86         struct dentry *dentry;
  87 };
  88
  89 static void gss_free_ctx(struct gss_cl_ctx *);
  90 static struct rpc_pipe_ops gss_upcall_ops;
  91
  92 static inline struct gss_cl_ctx *
  93 gss_get_ctx(struct gss_cl_ctx *ctx)
  94 {
  95         atomic_inc(&ctx->count);
  96         return ctx;
  97 }
  98
  99 static inline void
 100 gss_put_ctx(struct gss_cl_ctx *ctx)
 101 {
 102         if (atomic_dec_and_test(&ctx->count))
 103                 gss_free_ctx(ctx);
 104 }
 105
 106 /* gss_cred_set_ctx:
 107  * called by gss_upcall_callback and gss_create_upcall in order
 108  * to set the gss context. The actual exchange of an old context
 109  * and a new one is protected by the inode->i_lock.
 110  */
 111 static void
 112 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 113 {
 114         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 115
 116         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 117                 return;
 118         gss_get_ctx(ctx);
 119         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 120         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 121         smp_mb__before_clear_bit();
 122         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 123 }
 124
 125 static const void *
 126 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 127 {
 128         const void *q = (const void *)((const char *)p + len);
 129         if (unlikely(q > end || q < p))
 130                 return ERR_PTR(-EFAULT);
 131         memcpy(res, p, len);
 132         return q;
 133 }
 134
 135 static inline const void *
 136 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 137 {
 138         const void *q;
 139         unsigned int len;
 140
 141         p = simple_get_bytes(p, end, &len, sizeof(len));
 142         if (IS_ERR(p))
 143                 return p;
 144         q = (const void *)((const char *)p + len);
 145         if (unlikely(q > end || q < p))
 146                 return ERR_PTR(-EFAULT);
 147         dest->data = kmemdup(p, len, GFP_KERNEL);
 148         if (unlikely(dest->data == NULL))
 149                 return ERR_PTR(-ENOMEM);
 150         dest->len = len;
 151         return q;
 152 }
 153
 154 static struct gss_cl_ctx *
 155 gss_cred_get_ctx(struct rpc_cred *cred)
 156 {
 157         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 158         struct gss_cl_ctx *ctx = NULL;
 159
 160         rcu_read_lock();
 161         if (gss_cred->gc_ctx)
 162                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 163         rcu_read_unlock();
 164         return ctx;
 165 }
 166
 167 static struct gss_cl_ctx *
 168 gss_alloc_context(void)
 169 {
 170         struct gss_cl_ctx *ctx;
 171
 172         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 173         if (ctx != NULL) {
 174                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 175                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 176                 spin_lock_init(&ctx->gc_seq_lock);
 177                 atomic_set(&ctx->count,1);
 178         }
 179         return ctx;
 180 }
 181
 182 #define GSSD_MIN_TIMEOUT (60 * 60)
 183 static const void *
 184 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 185 {
 186         const void *q;
 187         unsigned int seclen;
 188         unsigned int timeout;
 189         u32 window_size;
 190         int ret;
 191
 192         /* First unsigned int gives the lifetime (in seconds) of the cred */
 193         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 194         if (IS_ERR(p))
 195                 goto err;
 196         if (timeout == 0)
 197                 timeout = GSSD_MIN_TIMEOUT;
 198         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 199         /* Sequence number window. Determines the maximum number of simultaneous requests */
 200         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 201         if (IS_ERR(p))
 202                 goto err;
 203         ctx->gc_win = window_size;
 204         /* gssd signals an error by passing ctx->gc_win = 0: */
 205         if (ctx->gc_win == 0) {
 206                 /* in which case, p points to  an error code which we ignore */
 207                 p = ERR_PTR(-EACCES);
 208                 goto err;
 209         }
 210         /* copy the opaque wire context */
 211         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 212         if (IS_ERR(p))
 213                 goto err;
 214         /* import the opaque security context */
 215         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 216         if (IS_ERR(p))
 217                 goto err;
 218         q = (const void *)((const char *)p + seclen);
 219         if (unlikely(q > end || q < p)) {
 220                 p = ERR_PTR(-EFAULT);
 221                 goto err;
 222         }
 223         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 224         if (ret < 0) {
 225                 p = ERR_PTR(ret);
 226                 goto err;
 227         }
 228         return q;
 229 err:
 230         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 231         return p;
 232 }
 233
 234
 235 struct gss_upcall_msg {
 236         atomic_t count;
 237         uid_t   uid;
 238         struct rpc_pipe_msg msg;
 239         struct list_head list;
 240         struct gss_auth *auth;
 241         struct rpc_wait_queue rpc_waitqueue;
 242         wait_queue_head_t waitqueue;
 243         struct gss_cl_ctx *ctx;
 244 };
 245
 246 static void
 247 gss_release_msg(struct gss_upcall_msg *gss_msg)
 248 {
 249         if (!atomic_dec_and_test(&gss_msg->count))
 250                 return;
 251         BUG_ON(!list_empty(&gss_msg->list));
 252         if (gss_msg->ctx != NULL)
 253                 gss_put_ctx(gss_msg->ctx);
 254         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 255         kfree(gss_msg);
 256 }
 257
 258 static struct gss_upcall_msg *
 259 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 260 {
 261         struct gss_upcall_msg *pos;
 262         list_for_each_entry(pos, &rpci->in_downcall, list) {
 263                 if (pos->uid != uid)
 264                         continue;
 265                 atomic_inc(&pos->count);
 266                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 267                 return pos;
 268         }
 269         dprintk("RPC:       gss_find_upcall found nothing\n");
 270         return NULL;
 271 }
 272
 273 /* Try to add a upcall to the pipefs queue.
 274  * If an upcall owned by our uid already exists, then we return a reference
 275  * to that upcall instead of adding the new upcall.
 276  */
 277 static inline struct gss_upcall_msg *
 278 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 279 {
 280         struct inode *inode = gss_auth->dentry->d_inode;
 281         struct rpc_inode *rpci = RPC_I(inode);
 282         struct gss_upcall_msg *old;
 283
 284         spin_lock(&inode->i_lock);
 285         old = __gss_find_upcall(rpci, gss_msg->uid);
 286         if (old == NULL) {
 287                 atomic_inc(&gss_msg->count);
 288                 list_add(&gss_msg->list, &rpci->in_downcall);
 289         } else
 290                 gss_msg = old;
 291         spin_unlock(&inode->i_lock);
 292         return gss_msg;
 293 }
 294
 295 static void
 296 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 297 {
 298         list_del_init(&gss_msg->list);
 299         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 300         wake_up_all(&gss_msg->waitqueue);
 301         atomic_dec(&gss_msg->count);
 302 }
 303
 304 static void
 305 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 306 {
 307         struct gss_auth *gss_auth = gss_msg->auth;
 308         struct inode *inode = gss_auth->dentry->d_inode;
 309
 310         if (list_empty(&gss_msg->list))
 311                 return;
 312         spin_lock(&inode->i_lock);
 313         if (!list_empty(&gss_msg->list))
 314                 __gss_unhash_msg(gss_msg);
 315         spin_unlock(&inode->i_lock);
 316 }
 317
 318 static void
 319 gss_upcall_callback(struct rpc_task *task)
 320 {
 321         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 322                         struct gss_cred, gc_base);
 323         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 324         struct inode *inode = gss_msg->auth->dentry->d_inode;
 325
 326         spin_lock(&inode->i_lock);
 327         if (gss_msg->ctx)
 328                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 329         else
 330                 task->tk_status = gss_msg->msg.errno;
 331         gss_cred->gc_upcall = NULL;
 332         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 333         spin_unlock(&inode->i_lock);
 334         gss_release_msg(gss_msg);
 335 }
 336
 337 static inline struct gss_upcall_msg *
 338 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 339 {
 340         struct gss_upcall_msg *gss_msg;
 341
 342         gss_msg = kzalloc(sizeof(*gss_msg), GFP_KERNEL);
 343         if (gss_msg != NULL) {
 344                 INIT_LIST_HEAD(&gss_msg->list);
 345                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 346                 init_waitqueue_head(&gss_msg->waitqueue);
 347                 atomic_set(&gss_msg->count, 1);
 348                 gss_msg->msg.data = &gss_msg->uid;
 349                 gss_msg->msg.len = sizeof(gss_msg->uid);
 350                 gss_msg->uid = uid;
 351                 gss_msg->auth = gss_auth;
 352         }
 353         return gss_msg;
 354 }
 355
 356 static struct gss_upcall_msg *
 357 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 358 {
 359         struct gss_cred *gss_cred = container_of(cred,
 360                         struct gss_cred, gc_base);
 361         struct gss_upcall_msg *gss_new, *gss_msg;
 362         uid_t uid = cred->cr_uid;
 363
 364         /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
 365         if (gss_cred->gc_machine_cred != 0)
 366                 uid = 0;
 367
 368         gss_new = gss_alloc_msg(gss_auth, uid);
 369         if (gss_new == NULL)
 370                 return ERR_PTR(-ENOMEM);
 371         gss_msg = gss_add_msg(gss_auth, gss_new);
 372         if (gss_msg == gss_new) {
 373                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 374                 if (res) {
 375                         gss_unhash_msg(gss_new);
 376                         gss_msg = ERR_PTR(res);
 377                 }
 378         } else
 379                 gss_release_msg(gss_new);
 380         return gss_msg;
 381 }
 382
 383 static inline int
 384 gss_refresh_upcall(struct rpc_task *task)
 385 {
 386         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 387         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 388                         struct gss_auth, rpc_auth);
 389         struct gss_cred *gss_cred = container_of(cred,
 390                         struct gss_cred, gc_base);
 391         struct gss_upcall_msg *gss_msg;
 392         struct inode *inode = gss_auth->dentry->d_inode;
 393         int err = 0;
 394
 395         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 396                                                                 cred->cr_uid);
 397         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 398         if (IS_ERR(gss_msg)) {
 399                 err = PTR_ERR(gss_msg);
 400                 goto out;
 401         }
 402         spin_lock(&inode->i_lock);
 403         if (gss_cred->gc_upcall != NULL)
 404                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 405         else if (gss_msg->ctx != NULL) {
 406                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 407                 gss_cred->gc_upcall = NULL;
 408                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 409         } else if (gss_msg->msg.errno >= 0) {
 410                 task->tk_timeout = 0;
 411                 gss_cred->gc_upcall = gss_msg;
 412                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 413                 atomic_inc(&gss_msg->count);
 414                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 415         } else
 416                 err = gss_msg->msg.errno;
 417         spin_unlock(&inode->i_lock);
 418         gss_release_msg(gss_msg);
 419 out:
 420         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 421                         task->tk_pid, cred->cr_uid, err);
 422         return err;
 423 }
 424
 425 static inline int
 426 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 427 {
 428         struct inode *inode = gss_auth->dentry->d_inode;
 429         struct rpc_cred *cred = &gss_cred->gc_base;
 430         struct gss_upcall_msg *gss_msg;
 431         DEFINE_WAIT(wait);
 432         int err = 0;
 433
 434         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 435         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 436         if (IS_ERR(gss_msg)) {
 437                 err = PTR_ERR(gss_msg);
 438                 goto out;
 439         }
 440         for (;;) {
 441                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 442                 spin_lock(&inode->i_lock);
 443                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 444                         break;
 445                 }
 446                 spin_unlock(&inode->i_lock);
 447                 if (signalled()) {
 448                         err = -ERESTARTSYS;
 449                         goto out_intr;
 450                 }
 451                 schedule();
 452         }
 453         if (gss_msg->ctx)
 454                 gss_cred_set_ctx(cred, gss_msg->ctx);
 455         else
 456                 err = gss_msg->msg.errno;
 457         spin_unlock(&inode->i_lock);
 458 out_intr:
 459         finish_wait(&gss_msg->waitqueue, &wait);
 460         gss_release_msg(gss_msg);
 461 out:
 462         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 463                         cred->cr_uid, err);
 464         return err;
 465 }
 466
 467 static ssize_t
 468 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 469                 char __user *dst, size_t buflen)
 470 {
 471         char *data = (char *)msg->data + msg->copied;
 472         size_t mlen = min(msg->len, buflen);
 473         unsigned long left;
 474
 475         left = copy_to_user(dst, data, mlen);
 476         if (left == mlen) {
 477                 msg->errno = -EFAULT;
 478                 return -EFAULT;
 479         }
 480
 481         mlen -= left;
 482         msg->copied += mlen;
 483         msg->errno = 0;
 484         return mlen;
 485 }
 486
 487 #define MSG_BUF_MAXSIZE 1024
 488
 489 static ssize_t
 490 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 491 {
 492         const void *p, *end;
 493         void *buf;
 494         struct rpc_clnt *clnt;
 495         struct gss_upcall_msg *gss_msg;
 496         struct inode *inode = filp->f_path.dentry->d_inode;
 497         struct gss_cl_ctx *ctx;
 498         uid_t uid;
 499         ssize_t err = -EFBIG;
 500
 501         if (mlen > MSG_BUF_MAXSIZE)
 502                 goto out;
 503         err = -ENOMEM;
 504         buf = kmalloc(mlen, GFP_KERNEL);
 505         if (!buf)
 506                 goto out;
 507
 508         clnt = RPC_I(inode)->private;
 509         err = -EFAULT;
 510         if (copy_from_user(buf, src, mlen))
 511                 goto err;
 512
 513         end = (const void *)((char *)buf + mlen);
 514         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 515         if (IS_ERR(p)) {
 516                 err = PTR_ERR(p);
 517                 goto err;
 518         }
 519
 520         err = -ENOMEM;
 521         ctx = gss_alloc_context();
 522         if (ctx == NULL)
 523                 goto err;
 524
 525         err = -ENOENT;
 526         /* Find a matching upcall */
 527         spin_lock(&inode->i_lock);
 528         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 529         if (gss_msg == NULL) {
 530                 spin_unlock(&inode->i_lock);
 531                 goto err_put_ctx;
 532         }
 533         list_del_init(&gss_msg->list);
 534         spin_unlock(&inode->i_lock);
 535
 536         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 537         if (IS_ERR(p)) {
 538                 err = PTR_ERR(p);
 539                 gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
 540                 goto err_release_msg;
 541         }
 542         gss_msg->ctx = gss_get_ctx(ctx);
 543         err = mlen;
 544
 545 err_release_msg:
 546         spin_lock(&inode->i_lock);
 547         __gss_unhash_msg(gss_msg);
 548         spin_unlock(&inode->i_lock);
 549         gss_release_msg(gss_msg);
 550 err_put_ctx:
 551         gss_put_ctx(ctx);
 552 err:
 553         kfree(buf);
 554 out:
 555         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 556         return err;
 557 }
 558
 559 static void
 560 gss_pipe_release(struct inode *inode)
 561 {
 562         struct rpc_inode *rpci = RPC_I(inode);
 563         struct gss_upcall_msg *gss_msg;
 564
 565         spin_lock(&inode->i_lock);
 566         while (!list_empty(&rpci->in_downcall)) {
 567
 568                 gss_msg = list_entry(rpci->in_downcall.next,
 569                                 struct gss_upcall_msg, list);
 570                 gss_msg->msg.errno = -EPIPE;
 571                 atomic_inc(&gss_msg->count);
 572                 __gss_unhash_msg(gss_msg);
 573                 spin_unlock(&inode->i_lock);
 574                 gss_release_msg(gss_msg);
 575                 spin_lock(&inode->i_lock);
 576         }
 577         spin_unlock(&inode->i_lock);
 578 }
 579
 580 static void
 581 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 582 {
 583         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 584         static unsigned long ratelimit;
 585
 586         if (msg->errno < 0) {
 587                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 588                                 gss_msg);
 589                 atomic_inc(&gss_msg->count);
 590                 gss_unhash_msg(gss_msg);
 591                 if (msg->errno == -ETIMEDOUT) {
 592                         unsigned long now = jiffies;
 593                         if (time_after(now, ratelimit)) {
 594                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 595                                                     "Please check user daemon is running!\n");
 596                                 ratelimit = now + 15*HZ;
 597                         }
 598                 }
 599                 gss_release_msg(gss_msg);
 600         }
 601 }
 602
 603 /*
 604  * NOTE: we have the opportunity to use different
 605  * parameters based on the input flavor (which must be a pseudoflavor)
 606  */
 607 static struct rpc_auth *
 608 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 609 {
 610         struct gss_auth *gss_auth;
 611         struct rpc_auth * auth;
 612         int err = -ENOMEM; /* XXX? */
 613
 614         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 615
 616         if (!try_module_get(THIS_MODULE))
 617                 return ERR_PTR(err);
 618         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 619                 goto out_dec;
 620         gss_auth->client = clnt;
 621         err = -EINVAL;
 622         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 623         if (!gss_auth->mech) {
 624                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 625                                 __func__, flavor);
 626                 goto err_free;
 627         }
 628         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 629         if (gss_auth->service == 0)
 630                 goto err_put_mech;
 631         auth = &gss_auth->rpc_auth;
 632         auth->au_cslack = GSS_CRED_SLACK >> 2;
 633         auth->au_rslack = GSS_VERF_SLACK >> 2;
 634         auth->au_ops = &authgss_ops;
 635         auth->au_flavor = flavor;
 636         atomic_set(&auth->au_count, 1);
 637         kref_init(&gss_auth->kref);
 638
 639         gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
 640                         clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 641         if (IS_ERR(gss_auth->dentry)) {
 642                 err = PTR_ERR(gss_auth->dentry);
 643                 goto err_put_mech;
 644         }
 645
 646         err = rpcauth_init_credcache(auth);
 647         if (err)
 648                 goto err_unlink_pipe;
 649
 650         return auth;
 651 err_unlink_pipe:
 652         rpc_unlink(gss_auth->dentry);
 653 err_put_mech:
 654         gss_mech_put(gss_auth->mech);
 655 err_free:
 656         kfree(gss_auth);
 657 out_dec:
 658         module_put(THIS_MODULE);
 659         return ERR_PTR(err);
 660 }
 661
 662 static void
 663 gss_free(struct gss_auth *gss_auth)
 664 {
 665         rpc_unlink(gss_auth->dentry);
 666         gss_auth->dentry = NULL;
 667         gss_mech_put(gss_auth->mech);
 668
 669         kfree(gss_auth);
 670         module_put(THIS_MODULE);
 671 }
 672
 673 static void
 674 gss_free_callback(struct kref *kref)
 675 {
 676         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 677
 678         gss_free(gss_auth);
 679 }
 680
 681 static void
 682 gss_destroy(struct rpc_auth *auth)
 683 {
 684         struct gss_auth *gss_auth;
 685
 686         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 687                         auth, auth->au_flavor);
 688
 689         rpcauth_destroy_credcache(auth);
 690
 691         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 692         kref_put(&gss_auth->kref, gss_free_callback);
 693 }
 694
 695 /*
 696  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 697  * to the server with the GSS control procedure field set to
 698  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 699  * all RPCSEC_GSS state associated with that context.
 700  */
 701 static int
 702 gss_destroying_context(struct rpc_cred *cred)
 703 {
 704         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 705         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 706         struct rpc_task *task;
 707
 708         if (gss_cred->gc_ctx == NULL ||
 709             test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 710                 return 0;
 711
 712         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 713         cred->cr_ops = &gss_nullops;
 714
 715         /* Take a reference to ensure the cred will be destroyed either
 716          * by the RPC call or by the put_rpccred() below */
 717         get_rpccred(cred);
 718
 719         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 720         if (!IS_ERR(task))
 721                 rpc_put_task(task);
 722
 723         put_rpccred(cred);
 724         return 1;
 725 }
 726
 727 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 728  * to create a new cred or context, so they check that things have been
 729  * allocated before freeing them. */
 730 static void
 731 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 732 {
 733         dprintk("RPC:       gss_free_ctx\n");
 734
 735         kfree(ctx->gc_wire_ctx.data);
 736         kfree(ctx);
 737 }
 738
 739 static void
 740 gss_free_ctx_callback(struct rcu_head *head)
 741 {
 742         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 743         gss_do_free_ctx(ctx);
 744 }
 745
 746 static void
 747 gss_free_ctx(struct gss_cl_ctx *ctx)
 748 {
 749         struct gss_ctx *gc_gss_ctx;
 750
 751         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 752         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 753         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 754         if (gc_gss_ctx)
 755                 gss_delete_sec_context(&gc_gss_ctx);
 756 }
 757
 758 static void
 759 gss_free_cred(struct gss_cred *gss_cred)
 760 {
 761         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 762         kfree(gss_cred);
 763 }
 764
 765 static void
 766 gss_free_cred_callback(struct rcu_head *head)
 767 {
 768         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 769         gss_free_cred(gss_cred);
 770 }
 771
 772 static void
 773 gss_destroy_cred(struct rpc_cred *cred)
 774 {
 775         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 776         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 777         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 778
 779         if (gss_destroying_context(cred))
 780                 return;
 781         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 782         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 783         if (ctx)
 784                 gss_put_ctx(ctx);
 785         kref_put(&gss_auth->kref, gss_free_callback);
 786 }
 787
 788 /*
 789  * Lookup RPCSEC_GSS cred for the current process
 790  */
 791 static struct rpc_cred *
 792 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 793 {
 794         return rpcauth_lookup_credcache(auth, acred, flags);
 795 }
 796
 797 static struct rpc_cred *
 798 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 799 {
 800         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 801         struct gss_cred *cred = NULL;
 802         int err = -ENOMEM;
 803
 804         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 805                 acred->uid, auth->au_flavor);
 806
 807         if (!(cred = kzalloc(sizeof(*cred), GFP_KERNEL)))
 808                 goto out_err;
 809
 810         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 811         /*
 812          * Note: in order to force a call to call_refresh(), we deliberately
 813          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 814          */
 815         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 816         cred->gc_service = gss_auth->service;
 817         cred->gc_machine_cred = acred->machine_cred;
 818         kref_get(&gss_auth->kref);
 819         return &cred->gc_base;
 820
 821 out_err:
 822         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
 823         return ERR_PTR(err);
 824 }
 825
 826 static int
 827 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 828 {
 829         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 830         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
 831         int err;
 832
 833         do {
 834                 err = gss_create_upcall(gss_auth, gss_cred);
 835         } while (err == -EAGAIN);
 836         return err;
 837 }
 838
 839 static int
 840 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 841 {
 842         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 843
 844         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 845                 goto out;
 846         /* Don't match with creds that have expired. */
 847         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 848                 return 0;
 849         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
 850                 return 0;
 851 out:
 852         if (acred->machine_cred != gss_cred->gc_machine_cred)
 853                 return 0;
 854         return (rc->cr_uid == acred->uid);
 855 }
 856
 857 /*
 858 * Marshal credentials.
 859 * Maybe we should keep a cached credential for performance reasons.
 860 */
 861 static __be32 *
 862 gss_marshal(struct rpc_task *task, __be32 *p)
 863 {
 864         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 865         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 866                                                  gc_base);
 867         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 868         __be32          *cred_len;
 869         struct rpc_rqst *req = task->tk_rqstp;
 870         u32             maj_stat = 0;
 871         struct xdr_netobj mic;
 872         struct kvec     iov;
 873         struct xdr_buf  verf_buf;
 874
 875         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
 876
 877         *p++ = htonl(RPC_AUTH_GSS);
 878         cred_len = p++;
 879
 880         spin_lock(&ctx->gc_seq_lock);
 881         req->rq_seqno = ctx->gc_seq++;
 882         spin_unlock(&ctx->gc_seq_lock);
 883
 884         *p++ = htonl((u32) RPC_GSS_VERSION);
 885         *p++ = htonl((u32) ctx->gc_proc);
 886         *p++ = htonl((u32) req->rq_seqno);
 887         *p++ = htonl((u32) gss_cred->gc_service);
 888         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 889         *cred_len = htonl((p - (cred_len + 1)) << 2);
 890
 891         /* We compute the checksum for the verifier over the xdr-encoded bytes
 892          * starting with the xid and ending at the end of the credential: */
 893         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 894                                         req->rq_snd_buf.head[0].iov_base);
 895         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 896         xdr_buf_from_iov(&iov, &verf_buf);
 897
 898         /* set verifier flavor*/
 899         *p++ = htonl(RPC_AUTH_GSS);
 900
 901         mic.data = (u8 *)(p + 1);
 902         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 903         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 904                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 905         } else if (maj_stat != 0) {
 906                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 907                 goto out_put_ctx;
 908         }
 909         p = xdr_encode_opaque(p, NULL, mic.len);
 910         gss_put_ctx(ctx);
 911         return p;
 912 out_put_ctx:
 913         gss_put_ctx(ctx);
 914         return NULL;
 915 }
 916
 917 static int gss_renew_cred(struct rpc_task *task)
 918 {
 919         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
 920         struct gss_cred *gss_cred = container_of(oldcred,
 921                                                  struct gss_cred,
 922                                                  gc_base);
 923         struct rpc_auth *auth = oldcred->cr_auth;
 924         struct auth_cred acred = {
 925                 .uid = oldcred->cr_uid,
 926                 .machine_cred = gss_cred->gc_machine_cred,
 927         };
 928         struct rpc_cred *new;
 929
 930         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
 931         if (IS_ERR(new))
 932                 return PTR_ERR(new);
 933         task->tk_msg.rpc_cred = new;
 934         put_rpccred(oldcred);
 935         return 0;
 936 }
 937
 938 /*
 939 * Refresh credentials. XXX - finish
 940 */
 941 static int
 942 gss_refresh(struct rpc_task *task)
 943 {
 944         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 945         int ret = 0;
 946
 947         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 948                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
 949                 ret = gss_renew_cred(task);
 950                 if (ret < 0)
 951                         goto out;
 952                 cred = task->tk_msg.rpc_cred;
 953         }
 954
 955         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 956                 ret = gss_refresh_upcall(task);
 957 out:
 958         return ret;
 959 }
 960
 961 /* Dummy refresh routine: used only when destroying the context */
 962 static int
 963 gss_refresh_null(struct rpc_task *task)
 964 {
 965         return -EACCES;
 966 }
 967
 968 static __be32 *
 969 gss_validate(struct rpc_task *task, __be32 *p)
 970 {
 971         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 972         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 973         __be32          seq;
 974         struct kvec     iov;
 975         struct xdr_buf  verf_buf;
 976         struct xdr_netobj mic;
 977         u32             flav,len;
 978         u32             maj_stat;
 979
 980         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
 981
 982         flav = ntohl(*p++);
 983         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 984                 goto out_bad;
 985         if (flav != RPC_AUTH_GSS)
 986                 goto out_bad;
 987         seq = htonl(task->tk_rqstp->rq_seqno);
 988         iov.iov_base = &seq;
 989         iov.iov_len = sizeof(seq);
 990         xdr_buf_from_iov(&iov, &verf_buf);
 991         mic.data = (u8 *)p;
 992         mic.len = len;
 993
 994         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 995         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 996                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 997         if (maj_stat) {
 998                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
 999                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1000                 goto out_bad;
1001         }
1002         /* We leave it to unwrap to calculate au_rslack. For now we just
1003          * calculate the length of the verifier: */
1004         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1005         gss_put_ctx(ctx);
1006         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1007                         task->tk_pid);
1008         return p + XDR_QUADLEN(len);
1009 out_bad:
1010         gss_put_ctx(ctx);
1011         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1012         return NULL;
1013 }
1014
1015 static inline int
1016 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1017                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1018 {
1019         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1020         struct xdr_buf  integ_buf;
1021         __be32          *integ_len = NULL;
1022         struct xdr_netobj mic;
1023         u32             offset;
1024         __be32          *q;
1025         struct kvec     *iov;
1026         u32             maj_stat = 0;
1027         int             status = -EIO;
1028
1029         integ_len = p++;
1030         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1031         *p++ = htonl(rqstp->rq_seqno);
1032
1033         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1034         if (status)
1035                 return status;
1036
1037         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1038                                 offset, snd_buf->len - offset))
1039                 return status;
1040         *integ_len = htonl(integ_buf.len);
1041
1042         /* guess whether we're in the head or the tail: */
1043         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1044                 iov = snd_buf->tail;
1045         else
1046                 iov = snd_buf->head;
1047         p = iov->iov_base + iov->iov_len;
1048         mic.data = (u8 *)(p + 1);
1049
1050         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1051         status = -EIO; /* XXX? */
1052         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1053                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1054         else if (maj_stat)
1055                 return status;
1056         q = xdr_encode_opaque(p, NULL, mic.len);
1057
1058         offset = (u8 *)q - (u8 *)p;
1059         iov->iov_len += offset;
1060         snd_buf->len += offset;
1061         return 0;
1062 }
1063
1064 static void
1065 priv_release_snd_buf(struct rpc_rqst *rqstp)
1066 {
1067         int i;
1068
1069         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1070                 __free_page(rqstp->rq_enc_pages[i]);
1071         kfree(rqstp->rq_enc_pages);
1072 }
1073
1074 static int
1075 alloc_enc_pages(struct rpc_rqst *rqstp)
1076 {
1077         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1078         int first, last, i;
1079
1080         if (snd_buf->page_len == 0) {
1081                 rqstp->rq_enc_pages_num = 0;
1082                 return 0;
1083         }
1084
1085         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1086         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1087         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1088         rqstp->rq_enc_pages
1089                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1090                                 GFP_NOFS);
1091         if (!rqstp->rq_enc_pages)
1092                 goto out;
1093         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1094                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1095                 if (rqstp->rq_enc_pages[i] == NULL)
1096                         goto out_free;
1097         }
1098         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1099         return 0;
1100 out_free:
1101         for (i--; i >= 0; i--) {
1102                 __free_page(rqstp->rq_enc_pages[i]);
1103         }
1104 out:
1105         return -EAGAIN;
1106 }
1107
1108 static inline int
1109 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1110                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1111 {
1112         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1113         u32             offset;
1114         u32             maj_stat;
1115         int             status;
1116         __be32          *opaque_len;
1117         struct page     **inpages;
1118         int             first;
1119         int             pad;
1120         struct kvec     *iov;
1121         char            *tmp;
1122
1123         opaque_len = p++;
1124         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1125         *p++ = htonl(rqstp->rq_seqno);
1126
1127         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1128         if (status)
1129                 return status;
1130
1131         status = alloc_enc_pages(rqstp);
1132         if (status)
1133                 return status;
1134         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1135         inpages = snd_buf->pages + first;
1136         snd_buf->pages = rqstp->rq_enc_pages;
1137         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1138         /* Give the tail its own page, in case we need extra space in the
1139          * head when wrapping: */
1140         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1141                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1142                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1143                 snd_buf->tail[0].iov_base = tmp;
1144         }
1145         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1146         /* RPC_SLACK_SPACE should prevent this ever happening: */
1147         BUG_ON(snd_buf->len > snd_buf->buflen);
1148         status = -EIO;
1149         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1150          * done anyway, so it's safe to put the request on the wire: */
1151         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1152                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1153         else if (maj_stat)
1154                 return status;
1155
1156         *opaque_len = htonl(snd_buf->len - offset);
1157         /* guess whether we're in the head or the tail: */
1158         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1159                 iov = snd_buf->tail;
1160         else
1161                 iov = snd_buf->head;
1162         p = iov->iov_base + iov->iov_len;
1163         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1164         memset(p, 0, pad);
1165         iov->iov_len += pad;
1166         snd_buf->len += pad;
1167
1168         return 0;
1169 }
1170
1171 static int
1172 gss_wrap_req(struct rpc_task *task,
1173              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1174 {
1175         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1176         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1177                         gc_base);
1178         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1179         int             status = -EIO;
1180
1181         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1182         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1183                 /* The spec seems a little ambiguous here, but I think that not
1184                  * wrapping context destruction requests makes the most sense.
1185                  */
1186                 status = rpc_call_xdrproc(encode, rqstp, p, obj);
1187                 goto out;
1188         }
1189         switch (gss_cred->gc_service) {
1190                 case RPC_GSS_SVC_NONE:
1191                         status = rpc_call_xdrproc(encode, rqstp, p, obj);
1192                         break;
1193                 case RPC_GSS_SVC_INTEGRITY:
1194                         status = gss_wrap_req_integ(cred, ctx, encode,
1195                                                                 rqstp, p, obj);
1196                         break;
1197                 case RPC_GSS_SVC_PRIVACY:
1198                         status = gss_wrap_req_priv(cred, ctx, encode,
1199                                         rqstp, p, obj);
1200                         break;
1201         }
1202 out:
1203         gss_put_ctx(ctx);
1204         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1205         return status;
1206 }
1207
1208 static inline int
1209 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1210                 struct rpc_rqst *rqstp, __be32 **p)
1211 {
1212         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1213         struct xdr_buf integ_buf;
1214         struct xdr_netobj mic;
1215         u32 data_offset, mic_offset;
1216         u32 integ_len;
1217         u32 maj_stat;
1218         int status = -EIO;
1219
1220         integ_len = ntohl(*(*p)++);
1221         if (integ_len & 3)
1222                 return status;
1223         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1224         mic_offset = integ_len + data_offset;
1225         if (mic_offset > rcv_buf->len)
1226                 return status;
1227         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1228                 return status;
1229
1230         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1231                                 mic_offset - data_offset))
1232                 return status;
1233
1234         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1235                 return status;
1236
1237         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1238         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1239                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1240         if (maj_stat != GSS_S_COMPLETE)
1241                 return status;
1242         return 0;
1243 }
1244
1245 static inline int
1246 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1247                 struct rpc_rqst *rqstp, __be32 **p)
1248 {
1249         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1250         u32 offset;
1251         u32 opaque_len;
1252         u32 maj_stat;
1253         int status = -EIO;
1254
1255         opaque_len = ntohl(*(*p)++);
1256         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1257         if (offset + opaque_len > rcv_buf->len)
1258                 return status;
1259         /* remove padding: */
1260         rcv_buf->len = offset + opaque_len;
1261
1262         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1263         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1264                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1265         if (maj_stat != GSS_S_COMPLETE)
1266                 return status;
1267         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1268                 return status;
1269
1270         return 0;
1271 }
1272
1273
1274 static int
1275 gss_unwrap_resp(struct rpc_task *task,
1276                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1277 {
1278         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1279         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1280                         gc_base);
1281         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1282         __be32          *savedp = p;
1283         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1284         int             savedlen = head->iov_len;
1285         int             status = -EIO;
1286
1287         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1288                 goto out_decode;
1289         switch (gss_cred->gc_service) {
1290                 case RPC_GSS_SVC_NONE:
1291                         break;
1292                 case RPC_GSS_SVC_INTEGRITY:
1293                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1294                         if (status)
1295                                 goto out;
1296                         break;
1297                 case RPC_GSS_SVC_PRIVACY:
1298                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1299                         if (status)
1300                                 goto out;
1301                         break;
1302         }
1303         /* take into account extra slack for integrity and privacy cases: */
1304         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1305                                                 + (savedlen - head->iov_len);
1306 out_decode:
1307         status = rpc_call_xdrproc(decode, rqstp, p, obj);
1308 out:
1309         gss_put_ctx(ctx);
1310         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1311                         status);
1312         return status;
1313 }
1314
1315 static const struct rpc_authops authgss_ops = {
1316         .owner          = THIS_MODULE,
1317         .au_flavor      = RPC_AUTH_GSS,
1318         .au_name        = "RPCSEC_GSS",
1319         .create         = gss_create,
1320         .destroy        = gss_destroy,
1321         .lookup_cred    = gss_lookup_cred,
1322         .crcreate       = gss_create_cred
1323 };
1324
1325 static const struct rpc_credops gss_credops = {
1326         .cr_name        = "AUTH_GSS",
1327         .crdestroy      = gss_destroy_cred,
1328         .cr_init        = gss_cred_init,
1329         .crbind         = rpcauth_generic_bind_cred,
1330         .crmatch        = gss_match,
1331         .crmarshal      = gss_marshal,
1332         .crrefresh      = gss_refresh,
1333         .crvalidate     = gss_validate,
1334         .crwrap_req     = gss_wrap_req,
1335         .crunwrap_resp  = gss_unwrap_resp,
1336 };
1337
1338 static const struct rpc_credops gss_nullops = {
1339         .cr_name        = "AUTH_GSS",
1340         .crdestroy      = gss_destroy_cred,
1341         .crbind         = rpcauth_generic_bind_cred,
1342         .crmatch        = gss_match,
1343         .crmarshal      = gss_marshal,
1344         .crrefresh      = gss_refresh_null,
1345         .crvalidate     = gss_validate,
1346         .crwrap_req     = gss_wrap_req,
1347         .crunwrap_resp  = gss_unwrap_resp,
1348 };
1349
1350 static struct rpc_pipe_ops gss_upcall_ops = {
1351         .upcall         = gss_pipe_upcall,
1352         .downcall       = gss_pipe_downcall,
1353         .destroy_msg    = gss_pipe_destroy_msg,
1354         .release_pipe   = gss_pipe_release,
1355 };
1356
1357 /*
1358  * Initialize RPCSEC_GSS module
1359  */
1360 static int __init init_rpcsec_gss(void)
1361 {
1362         int err = 0;
1363
1364         err = rpcauth_register(&authgss_ops);
1365         if (err)
1366                 goto out;
1367         err = gss_svc_init();
1368         if (err)
1369                 goto out_unregister;
1370         return 0;
1371 out_unregister:
1372         rpcauth_unregister(&authgss_ops);
1373 out:
1374         return err;
1375 }
1376
1377 static void __exit exit_rpcsec_gss(void)
1378 {
1379         gss_svc_shutdown();
1380         rpcauth_unregister(&authgss_ops);
1381 }
1382
1383 MODULE_LICENSE("GPL");
1384 module_init(init_rpcsec_gss)
1385 module_exit(exit_rpcsec_gss)