net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/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  * $Id$
  38  */
  39
  40
  41 #include <linux/module.h>
  42 #include <linux/init.h>
  43 #include <linux/types.h>
  44 #include <linux/slab.h>
  45 #include <linux/sched.h>
  46 #include <linux/sunrpc/clnt.h>
  47 #include <linux/sunrpc/auth.h>
  48 #include <linux/sunrpc/auth_gss.h>
  49 #include <linux/sunrpc/svcauth_gss.h>
  50 #include <linux/sunrpc/gss_err.h>
  51 #include <linux/workqueue.h>
  52 #include <linux/sunrpc/rpc_pipe_fs.h>
  53 #include <linux/sunrpc/gss_api.h>
  54 #include <asm/uaccess.h>
  55
  56 static struct rpc_authops authgss_ops;
  57
  58 static struct rpc_credops gss_credops;
  59
  60 #ifdef RPC_DEBUG
  61 # define RPCDBG_FACILITY        RPCDBG_AUTH
  62 #endif
  63
  64 #define NFS_NGROUPS     16
  65
  66 #define GSS_CRED_EXPIRE         (60 * HZ)       /* XXX: reasonable? */
  67 #define GSS_CRED_SLACK          1024            /* XXX: unused */
  68 /* length of a krb5 verifier (48), plus data added before arguments when
  69  * using integrity (two 4-byte integers): */
  70 #define GSS_VERF_SLACK          56
  71
  72 /* XXX this define must match the gssd define
  73 * as it is passed to gssd to signal the use of
  74 * machine creds should be part of the shared rpc interface */
  75
  76 #define CA_RUN_AS_MACHINE  0x00000200
  77
  78 /* dump the buffer in `emacs-hexl' style */
  79 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
  80
  81 static DEFINE_RWLOCK(gss_ctx_lock);
  82
  83 struct gss_auth {
  84         struct rpc_auth rpc_auth;
  85         struct gss_api_mech *mech;
  86         enum rpc_gss_svc service;
  87         struct list_head upcalls;
  88         struct rpc_clnt *client;
  89         struct dentry *dentry;
  90         char path[48];
  91         spinlock_t lock;
  92 };
  93
  94 static void gss_destroy_ctx(struct gss_cl_ctx *);
  95 static struct rpc_pipe_ops gss_upcall_ops;
  96
  97 void
  98 print_hexl(u32 *p, u_int length, u_int offset)
  99 {
 100         u_int i, j, jm;
 101         u8 c, *cp;
 102
 103         dprintk("RPC: print_hexl: length %d\n",length);
 104         dprintk("\n");
 105         cp = (u8 *) p;
 106
 107         for (i = 0; i < length; i += 0x10) {
 108                 dprintk("  %04x: ", (u_int)(i + offset));
 109                 jm = length - i;
 110                 jm = jm > 16 ? 16 : jm;
 111
 112                 for (j = 0; j < jm; j++) {
 113                         if ((j % 2) == 1)
 114                                 dprintk("%02x ", (u_int)cp[i+j]);
 115                         else
 116                                 dprintk("%02x", (u_int)cp[i+j]);
 117                 }
 118                 for (; j < 16; j++) {
 119                         if ((j % 2) == 1)
 120                                 dprintk("   ");
 121                         else
 122                                 dprintk("  ");
 123                 }
 124                 dprintk(" ");
 125
 126                 for (j = 0; j < jm; j++) {
 127                         c = cp[i+j];
 128                         c = isprint(c) ? c : '.';
 129                         dprintk("%c", c);
 130                 }
 131                 dprintk("\n");
 132         }
 133 }
 134
 135 EXPORT_SYMBOL(print_hexl);
 136
 137 static inline struct gss_cl_ctx *
 138 gss_get_ctx(struct gss_cl_ctx *ctx)
 139 {
 140         atomic_inc(&ctx->count);
 141         return ctx;
 142 }
 143
 144 static inline void
 145 gss_put_ctx(struct gss_cl_ctx *ctx)
 146 {
 147         if (atomic_dec_and_test(&ctx->count))
 148                 gss_destroy_ctx(ctx);
 149 }
 150
 151 static void
 152 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 153 {
 154         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 155         struct gss_cl_ctx *old;
 156         write_lock(&gss_ctx_lock);
 157         old = gss_cred->gc_ctx;
 158         gss_cred->gc_ctx = ctx;
 159         cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
 160         write_unlock(&gss_ctx_lock);
 161         if (old)
 162                 gss_put_ctx(old);
 163 }
 164
 165 static int
 166 gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
 167 {
 168         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 169         int res = 0;
 170
 171         read_lock(&gss_ctx_lock);
 172         if ((cred->cr_flags & RPCAUTH_CRED_UPTODATE) && gss_cred->gc_ctx)
 173                 res = 1;
 174         read_unlock(&gss_ctx_lock);
 175         return res;
 176 }
 177
 178 static const void *
 179 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 180 {
 181         const void *q = (const void *)((const char *)p + len);
 182         if (unlikely(q > end || q < p))
 183                 return ERR_PTR(-EFAULT);
 184         memcpy(res, p, len);
 185         return q;
 186 }
 187
 188 static inline const void *
 189 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 190 {
 191         const void *q;
 192         unsigned int len;
 193
 194         p = simple_get_bytes(p, end, &len, sizeof(len));
 195         if (IS_ERR(p))
 196                 return p;
 197         q = (const void *)((const char *)p + len);
 198         if (unlikely(q > end || q < p))
 199                 return ERR_PTR(-EFAULT);
 200         dest->data = kmalloc(len, GFP_KERNEL);
 201         if (unlikely(dest->data == NULL))
 202                 return ERR_PTR(-ENOMEM);
 203         dest->len = len;
 204         memcpy(dest->data, p, len);
 205         return q;
 206 }
 207
 208 static struct gss_cl_ctx *
 209 gss_cred_get_ctx(struct rpc_cred *cred)
 210 {
 211         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 212         struct gss_cl_ctx *ctx = NULL;
 213
 214         read_lock(&gss_ctx_lock);
 215         if (gss_cred->gc_ctx)
 216                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 217         read_unlock(&gss_ctx_lock);
 218         return ctx;
 219 }
 220
 221 static struct gss_cl_ctx *
 222 gss_alloc_context(void)
 223 {
 224         struct gss_cl_ctx *ctx;
 225
 226         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
 227         if (ctx != NULL) {
 228                 memset(ctx, 0, sizeof(*ctx));
 229                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 230                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 231                 spin_lock_init(&ctx->gc_seq_lock);
 232                 atomic_set(&ctx->count,1);
 233         }
 234         return ctx;
 235 }
 236
 237 #define GSSD_MIN_TIMEOUT (60 * 60)
 238 static const void *
 239 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 240 {
 241         const void *q;
 242         unsigned int seclen;
 243         unsigned int timeout;
 244         u32 window_size;
 245         int ret;
 246
 247         /* First unsigned int gives the lifetime (in seconds) of the cred */
 248         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 249         if (IS_ERR(p))
 250                 goto err;
 251         if (timeout == 0)
 252                 timeout = GSSD_MIN_TIMEOUT;
 253         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 254         /* Sequence number window. Determines the maximum number of simultaneous requests */
 255         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 256         if (IS_ERR(p))
 257                 goto err;
 258         ctx->gc_win = window_size;
 259         /* gssd signals an error by passing ctx->gc_win = 0: */
 260         if (ctx->gc_win == 0) {
 261                 /* in which case, p points to  an error code which we ignore */
 262                 p = ERR_PTR(-EACCES);
 263                 goto err;
 264         }
 265         /* copy the opaque wire context */
 266         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 267         if (IS_ERR(p))
 268                 goto err;
 269         /* import the opaque security context */
 270         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 271         if (IS_ERR(p))
 272                 goto err;
 273         q = (const void *)((const char *)p + seclen);
 274         if (unlikely(q > end || q < p)) {
 275                 p = ERR_PTR(-EFAULT);
 276                 goto err;
 277         }
 278         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 279         if (ret < 0) {
 280                 p = ERR_PTR(ret);
 281                 goto err;
 282         }
 283         return q;
 284 err:
 285         dprintk("RPC:      gss_fill_context returning %ld\n", -PTR_ERR(p));
 286         return p;
 287 }
 288
 289
 290 struct gss_upcall_msg {
 291         atomic_t count;
 292         uid_t   uid;
 293         struct rpc_pipe_msg msg;
 294         struct list_head list;
 295         struct gss_auth *auth;
 296         struct rpc_wait_queue rpc_waitqueue;
 297         wait_queue_head_t waitqueue;
 298         struct gss_cl_ctx *ctx;
 299 };
 300
 301 static void
 302 gss_release_msg(struct gss_upcall_msg *gss_msg)
 303 {
 304         if (!atomic_dec_and_test(&gss_msg->count))
 305                 return;
 306         BUG_ON(!list_empty(&gss_msg->list));
 307         if (gss_msg->ctx != NULL)
 308                 gss_put_ctx(gss_msg->ctx);
 309         kfree(gss_msg);
 310 }
 311
 312 static struct gss_upcall_msg *
 313 __gss_find_upcall(struct gss_auth *gss_auth, uid_t uid)
 314 {
 315         struct gss_upcall_msg *pos;
 316         list_for_each_entry(pos, &gss_auth->upcalls, list) {
 317                 if (pos->uid != uid)
 318                         continue;
 319                 atomic_inc(&pos->count);
 320                 dprintk("RPC:      gss_find_upcall found msg %p\n", pos);
 321                 return pos;
 322         }
 323         dprintk("RPC:      gss_find_upcall found nothing\n");
 324         return NULL;
 325 }
 326
 327 /* Try to add a upcall to the pipefs queue.
 328  * If an upcall owned by our uid already exists, then we return a reference
 329  * to that upcall instead of adding the new upcall.
 330  */
 331 static inline struct gss_upcall_msg *
 332 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 333 {
 334         struct gss_upcall_msg *old;
 335
 336         spin_lock(&gss_auth->lock);
 337         old = __gss_find_upcall(gss_auth, gss_msg->uid);
 338         if (old == NULL) {
 339                 atomic_inc(&gss_msg->count);
 340                 list_add(&gss_msg->list, &gss_auth->upcalls);
 341         } else
 342                 gss_msg = old;
 343         spin_unlock(&gss_auth->lock);
 344         return gss_msg;
 345 }
 346
 347 static void
 348 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 349 {
 350         if (list_empty(&gss_msg->list))
 351                 return;
 352         list_del_init(&gss_msg->list);
 353         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 354         wake_up_all(&gss_msg->waitqueue);
 355         atomic_dec(&gss_msg->count);
 356 }
 357
 358 static void
 359 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 360 {
 361         struct gss_auth *gss_auth = gss_msg->auth;
 362
 363         spin_lock(&gss_auth->lock);
 364         __gss_unhash_msg(gss_msg);
 365         spin_unlock(&gss_auth->lock);
 366 }
 367
 368 static void
 369 gss_upcall_callback(struct rpc_task *task)
 370 {
 371         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 372                         struct gss_cred, gc_base);
 373         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 374
 375         BUG_ON(gss_msg == NULL);
 376         if (gss_msg->ctx)
 377                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx));
 378         else
 379                 task->tk_status = gss_msg->msg.errno;
 380         spin_lock(&gss_msg->auth->lock);
 381         gss_cred->gc_upcall = NULL;
 382         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 383         spin_unlock(&gss_msg->auth->lock);
 384         gss_release_msg(gss_msg);
 385 }
 386
 387 static inline struct gss_upcall_msg *
 388 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 389 {
 390         struct gss_upcall_msg *gss_msg;
 391
 392         gss_msg = kmalloc(sizeof(*gss_msg), GFP_KERNEL);
 393         if (gss_msg != NULL) {
 394                 memset(gss_msg, 0, sizeof(*gss_msg));
 395                 INIT_LIST_HEAD(&gss_msg->list);
 396                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 397                 init_waitqueue_head(&gss_msg->waitqueue);
 398                 atomic_set(&gss_msg->count, 1);
 399                 gss_msg->msg.data = &gss_msg->uid;
 400                 gss_msg->msg.len = sizeof(gss_msg->uid);
 401                 gss_msg->uid = uid;
 402                 gss_msg->auth = gss_auth;
 403         }
 404         return gss_msg;
 405 }
 406
 407 static struct gss_upcall_msg *
 408 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 409 {
 410         struct gss_upcall_msg *gss_new, *gss_msg;
 411
 412         gss_new = gss_alloc_msg(gss_auth, cred->cr_uid);
 413         if (gss_new == NULL)
 414                 return ERR_PTR(-ENOMEM);
 415         gss_msg = gss_add_msg(gss_auth, gss_new);
 416         if (gss_msg == gss_new) {
 417                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 418                 if (res) {
 419                         gss_unhash_msg(gss_new);
 420                         gss_msg = ERR_PTR(res);
 421                 }
 422         } else
 423                 gss_release_msg(gss_new);
 424         return gss_msg;
 425 }
 426
 427 static inline int
 428 gss_refresh_upcall(struct rpc_task *task)
 429 {
 430         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 431         struct gss_auth *gss_auth = container_of(task->tk_client->cl_auth,
 432                         struct gss_auth, rpc_auth);
 433         struct gss_cred *gss_cred = container_of(cred,
 434                         struct gss_cred, gc_base);
 435         struct gss_upcall_msg *gss_msg;
 436         int err = 0;
 437
 438         dprintk("RPC: %4u gss_refresh_upcall for uid %u\n", task->tk_pid, cred->cr_uid);
 439         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 440         if (IS_ERR(gss_msg)) {
 441                 err = PTR_ERR(gss_msg);
 442                 goto out;
 443         }
 444         spin_lock(&gss_auth->lock);
 445         if (gss_cred->gc_upcall != NULL)
 446                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL);
 447         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 448                 task->tk_timeout = 0;
 449                 gss_cred->gc_upcall = gss_msg;
 450                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 451                 atomic_inc(&gss_msg->count);
 452                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL);
 453         } else
 454                 err = gss_msg->msg.errno;
 455         spin_unlock(&gss_auth->lock);
 456         gss_release_msg(gss_msg);
 457 out:
 458         dprintk("RPC: %4u gss_refresh_upcall for uid %u result %d\n", task->tk_pid,
 459                         cred->cr_uid, err);
 460         return err;
 461 }
 462
 463 static inline int
 464 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 465 {
 466         struct rpc_cred *cred = &gss_cred->gc_base;
 467         struct gss_upcall_msg *gss_msg;
 468         DEFINE_WAIT(wait);
 469         int err = 0;
 470
 471         dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid);
 472         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 473         if (IS_ERR(gss_msg)) {
 474                 err = PTR_ERR(gss_msg);
 475                 goto out;
 476         }
 477         for (;;) {
 478                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 479                 spin_lock(&gss_auth->lock);
 480                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 481                         spin_unlock(&gss_auth->lock);
 482                         break;
 483                 }
 484                 spin_unlock(&gss_auth->lock);
 485                 if (signalled()) {
 486                         err = -ERESTARTSYS;
 487                         goto out_intr;
 488                 }
 489                 schedule();
 490         }
 491         if (gss_msg->ctx)
 492                 gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));
 493         else
 494                 err = gss_msg->msg.errno;
 495 out_intr:
 496         finish_wait(&gss_msg->waitqueue, &wait);
 497         gss_release_msg(gss_msg);
 498 out:
 499         dprintk("RPC: gss_create_upcall for uid %u result %d\n", cred->cr_uid, err);
 500         return err;
 501 }
 502
 503 static ssize_t
 504 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 505                 char __user *dst, size_t buflen)
 506 {
 507         char *data = (char *)msg->data + msg->copied;
 508         ssize_t mlen = msg->len;
 509         ssize_t left;
 510
 511         if (mlen > buflen)
 512                 mlen = buflen;
 513         left = copy_to_user(dst, data, mlen);
 514         if (left < 0) {
 515                 msg->errno = left;
 516                 return left;
 517         }
 518         mlen -= left;
 519         msg->copied += mlen;
 520         msg->errno = 0;
 521         return mlen;
 522 }
 523
 524 #define MSG_BUF_MAXSIZE 1024
 525
 526 static ssize_t
 527 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 528 {
 529         const void *p, *end;
 530         void *buf;
 531         struct rpc_clnt *clnt;
 532         struct gss_auth *gss_auth;
 533         struct rpc_cred *cred;
 534         struct gss_upcall_msg *gss_msg;
 535         struct gss_cl_ctx *ctx;
 536         uid_t uid;
 537         int err = -EFBIG;
 538
 539         if (mlen > MSG_BUF_MAXSIZE)
 540                 goto out;
 541         err = -ENOMEM;
 542         buf = kmalloc(mlen, GFP_KERNEL);
 543         if (!buf)
 544                 goto out;
 545
 546         clnt = RPC_I(filp->f_dentry->d_inode)->private;
 547         err = -EFAULT;
 548         if (copy_from_user(buf, src, mlen))
 549                 goto err;
 550
 551         end = (const void *)((char *)buf + mlen);
 552         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 553         if (IS_ERR(p)) {
 554                 err = PTR_ERR(p);
 555                 goto err;
 556         }
 557
 558         err = -ENOMEM;
 559         ctx = gss_alloc_context();
 560         if (ctx == NULL)
 561                 goto err;
 562         err = 0;
 563         gss_auth = container_of(clnt->cl_auth, struct gss_auth, rpc_auth);
 564         p = gss_fill_context(p, end, ctx, gss_auth->mech);
 565         if (IS_ERR(p)) {
 566                 err = PTR_ERR(p);
 567                 if (err != -EACCES)
 568                         goto err_put_ctx;
 569         }
 570         spin_lock(&gss_auth->lock);
 571         gss_msg = __gss_find_upcall(gss_auth, uid);
 572         if (gss_msg) {
 573                 if (err == 0 && gss_msg->ctx == NULL)
 574                         gss_msg->ctx = gss_get_ctx(ctx);
 575                 gss_msg->msg.errno = err;
 576                 __gss_unhash_msg(gss_msg);
 577                 spin_unlock(&gss_auth->lock);
 578                 gss_release_msg(gss_msg);
 579         } else {
 580                 struct auth_cred acred = { .uid = uid };
 581                 spin_unlock(&gss_auth->lock);
 582                 cred = rpcauth_lookup_credcache(clnt->cl_auth, &acred, 0);
 583                 if (IS_ERR(cred)) {
 584                         err = PTR_ERR(cred);
 585                         goto err_put_ctx;
 586                 }
 587                 gss_cred_set_ctx(cred, gss_get_ctx(ctx));
 588         }
 589         gss_put_ctx(ctx);
 590         kfree(buf);
 591         dprintk("RPC:      gss_pipe_downcall returning length %Zu\n", mlen);
 592         return mlen;
 593 err_put_ctx:
 594         gss_put_ctx(ctx);
 595 err:
 596         kfree(buf);
 597 out:
 598         dprintk("RPC:      gss_pipe_downcall returning %d\n", err);
 599         return err;
 600 }
 601
 602 static void
 603 gss_pipe_release(struct inode *inode)
 604 {
 605         struct rpc_inode *rpci = RPC_I(inode);
 606         struct rpc_clnt *clnt;
 607         struct rpc_auth *auth;
 608         struct gss_auth *gss_auth;
 609
 610         clnt = rpci->private;
 611         auth = clnt->cl_auth;
 612         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 613         spin_lock(&gss_auth->lock);
 614         while (!list_empty(&gss_auth->upcalls)) {
 615                 struct gss_upcall_msg *gss_msg;
 616
 617                 gss_msg = list_entry(gss_auth->upcalls.next,
 618                                 struct gss_upcall_msg, list);
 619                 gss_msg->msg.errno = -EPIPE;
 620                 atomic_inc(&gss_msg->count);
 621                 __gss_unhash_msg(gss_msg);
 622                 spin_unlock(&gss_auth->lock);
 623                 gss_release_msg(gss_msg);
 624                 spin_lock(&gss_auth->lock);
 625         }
 626         spin_unlock(&gss_auth->lock);
 627 }
 628
 629 static void
 630 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 631 {
 632         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 633         static unsigned long ratelimit;
 634
 635         if (msg->errno < 0) {
 636                 dprintk("RPC:      gss_pipe_destroy_msg releasing msg %p\n",
 637                                 gss_msg);
 638                 atomic_inc(&gss_msg->count);
 639                 gss_unhash_msg(gss_msg);
 640                 if (msg->errno == -ETIMEDOUT || msg->errno == -EPIPE) {
 641                         unsigned long now = jiffies;
 642                         if (time_after(now, ratelimit)) {
 643                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 644                                                     "Please check user daemon is running!\n");
 645                                 ratelimit = now + 15*HZ;
 646                         }
 647                 }
 648                 gss_release_msg(gss_msg);
 649         }
 650 }
 651
 652 /*
 653  * NOTE: we have the opportunity to use different
 654  * parameters based on the input flavor (which must be a pseudoflavor)
 655  */
 656 static struct rpc_auth *
 657 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 658 {
 659         struct gss_auth *gss_auth;
 660         struct rpc_auth * auth;
 661         int err = -ENOMEM; /* XXX? */
 662
 663         dprintk("RPC:      creating GSS authenticator for client %p\n",clnt);
 664
 665         if (!try_module_get(THIS_MODULE))
 666                 return ERR_PTR(err);
 667         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 668                 goto out_dec;
 669         gss_auth->client = clnt;
 670         err = -EINVAL;
 671         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 672         if (!gss_auth->mech) {
 673                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
 674                                 __FUNCTION__, flavor);
 675                 goto err_free;
 676         }
 677         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 678         if (gss_auth->service == 0)
 679                 goto err_put_mech;
 680         INIT_LIST_HEAD(&gss_auth->upcalls);
 681         spin_lock_init(&gss_auth->lock);
 682         auth = &gss_auth->rpc_auth;
 683         auth->au_cslack = GSS_CRED_SLACK >> 2;
 684         auth->au_rslack = GSS_VERF_SLACK >> 2;
 685         auth->au_ops = &authgss_ops;
 686         auth->au_flavor = flavor;
 687         atomic_set(&auth->au_count, 1);
 688
 689         err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE);
 690         if (err)
 691                 goto err_put_mech;
 692
 693         snprintf(gss_auth->path, sizeof(gss_auth->path), "%s/%s",
 694                         clnt->cl_pathname,
 695                         gss_auth->mech->gm_name);
 696         gss_auth->dentry = rpc_mkpipe(gss_auth->path, clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 697         if (IS_ERR(gss_auth->dentry)) {
 698                 err = PTR_ERR(gss_auth->dentry);
 699                 goto err_put_mech;
 700         }
 701
 702         return auth;
 703 err_put_mech:
 704         gss_mech_put(gss_auth->mech);
 705 err_free:
 706         kfree(gss_auth);
 707 out_dec:
 708         module_put(THIS_MODULE);
 709         return ERR_PTR(err);
 710 }
 711
 712 static void
 713 gss_destroy(struct rpc_auth *auth)
 714 {
 715         struct gss_auth *gss_auth;
 716
 717         dprintk("RPC:      destroying GSS authenticator %p flavor %d\n",
 718                 auth, auth->au_flavor);
 719
 720         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 721         rpc_unlink(gss_auth->path);
 722         gss_mech_put(gss_auth->mech);
 723
 724         rpcauth_free_credcache(auth);
 725         kfree(gss_auth);
 726         module_put(THIS_MODULE);
 727 }
 728
 729 /* gss_destroy_cred (and gss_destroy_ctx) are used to clean up after failure
 730  * to create a new cred or context, so they check that things have been
 731  * allocated before freeing them. */
 732 static void
 733 gss_destroy_ctx(struct gss_cl_ctx *ctx)
 734 {
 735         dprintk("RPC:      gss_destroy_ctx\n");
 736
 737         if (ctx->gc_gss_ctx)
 738                 gss_delete_sec_context(&ctx->gc_gss_ctx);
 739
 740         kfree(ctx->gc_wire_ctx.data);
 741         kfree(ctx);
 742 }
 743
 744 static void
 745 gss_destroy_cred(struct rpc_cred *rc)
 746 {
 747         struct gss_cred *cred = container_of(rc, struct gss_cred, gc_base);
 748
 749         dprintk("RPC:      gss_destroy_cred \n");
 750
 751         if (cred->gc_ctx)
 752                 gss_put_ctx(cred->gc_ctx);
 753         kfree(cred);
 754 }
 755
 756 /*
 757  * Lookup RPCSEC_GSS cred for the current process
 758  */
 759 static struct rpc_cred *
 760 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int taskflags)
 761 {
 762         return rpcauth_lookup_credcache(auth, acred, taskflags);
 763 }
 764
 765 static struct rpc_cred *
 766 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int taskflags)
 767 {
 768         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 769         struct gss_cred *cred = NULL;
 770         int err = -ENOMEM;
 771
 772         dprintk("RPC:      gss_create_cred for uid %d, flavor %d\n",
 773                 acred->uid, auth->au_flavor);
 774
 775         if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL)))
 776                 goto out_err;
 777
 778         memset(cred, 0, sizeof(*cred));
 779         atomic_set(&cred->gc_count, 1);
 780         cred->gc_uid = acred->uid;
 781         /*
 782          * Note: in order to force a call to call_refresh(), we deliberately
 783          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 784          */
 785         cred->gc_flags = 0;
 786         cred->gc_base.cr_ops = &gss_credops;
 787         cred->gc_service = gss_auth->service;
 788         err = gss_create_upcall(gss_auth, cred);
 789         if (err < 0)
 790                 goto out_err;
 791
 792         return &cred->gc_base;
 793
 794 out_err:
 795         dprintk("RPC:      gss_create_cred failed with error %d\n", err);
 796         if (cred) gss_destroy_cred(&cred->gc_base);
 797         return ERR_PTR(err);
 798 }
 799
 800 static int
 801 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int taskflags)
 802 {
 803         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 804
 805         /* Don't match with creds that have expired. */
 806         if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 807                 return 0;
 808         return (rc->cr_uid == acred->uid);
 809 }
 810
 811 /*
 812 * Marshal credentials.
 813 * Maybe we should keep a cached credential for performance reasons.
 814 */
 815 static u32 *
 816 gss_marshal(struct rpc_task *task, u32 *p)
 817 {
 818         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 819         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 820                                                  gc_base);
 821         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 822         u32             *cred_len;
 823         struct rpc_rqst *req = task->tk_rqstp;
 824         u32             maj_stat = 0;
 825         struct xdr_netobj mic;
 826         struct kvec     iov;
 827         struct xdr_buf  verf_buf;
 828
 829         dprintk("RPC: %4u gss_marshal\n", task->tk_pid);
 830
 831         *p++ = htonl(RPC_AUTH_GSS);
 832         cred_len = p++;
 833
 834         spin_lock(&ctx->gc_seq_lock);
 835         req->rq_seqno = ctx->gc_seq++;
 836         spin_unlock(&ctx->gc_seq_lock);
 837
 838         *p++ = htonl((u32) RPC_GSS_VERSION);
 839         *p++ = htonl((u32) ctx->gc_proc);
 840         *p++ = htonl((u32) req->rq_seqno);
 841         *p++ = htonl((u32) gss_cred->gc_service);
 842         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 843         *cred_len = htonl((p - (cred_len + 1)) << 2);
 844
 845         /* We compute the checksum for the verifier over the xdr-encoded bytes
 846          * starting with the xid and ending at the end of the credential: */
 847         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
 848                                         req->rq_snd_buf.head[0].iov_base);
 849         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 850         xdr_buf_from_iov(&iov, &verf_buf);
 851
 852         /* set verifier flavor*/
 853         *p++ = htonl(RPC_AUTH_GSS);
 854
 855         mic.data = (u8 *)(p + 1);
 856         maj_stat = gss_get_mic(ctx->gc_gss_ctx,
 857                                GSS_C_QOP_DEFAULT,
 858                                &verf_buf, &mic);
 859         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 860                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 861         } else if (maj_stat != 0) {
 862                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 863                 goto out_put_ctx;
 864         }
 865         p = xdr_encode_opaque(p, NULL, mic.len);
 866         gss_put_ctx(ctx);
 867         return p;
 868 out_put_ctx:
 869         gss_put_ctx(ctx);
 870         return NULL;
 871 }
 872
 873 /*
 874 * Refresh credentials. XXX - finish
 875 */
 876 static int
 877 gss_refresh(struct rpc_task *task)
 878 {
 879
 880         if (!gss_cred_is_uptodate_ctx(task->tk_msg.rpc_cred))
 881                 return gss_refresh_upcall(task);
 882         return 0;
 883 }
 884
 885 static u32 *
 886 gss_validate(struct rpc_task *task, u32 *p)
 887 {
 888         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 889         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 890                                                 gc_base);
 891         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 892         u32             seq, qop_state;
 893         struct kvec     iov;
 894         struct xdr_buf  verf_buf;
 895         struct xdr_netobj mic;
 896         u32             flav,len;
 897         u32             maj_stat;
 898
 899         dprintk("RPC: %4u gss_validate\n", task->tk_pid);
 900
 901         flav = ntohl(*p++);
 902         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 903                 goto out_bad;
 904         if (flav != RPC_AUTH_GSS)
 905                 goto out_bad;
 906         seq = htonl(task->tk_rqstp->rq_seqno);
 907         iov.iov_base = &seq;
 908         iov.iov_len = sizeof(seq);
 909         xdr_buf_from_iov(&iov, &verf_buf);
 910         mic.data = (u8 *)p;
 911         mic.len = len;
 912
 913         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic, &qop_state);
 914         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 915                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 916         if (maj_stat)
 917                 goto out_bad;
 918        switch (gss_cred->gc_service) {
 919        case RPC_GSS_SVC_NONE:
 920                /* verifier data, flavor, length: */
 921                task->tk_auth->au_rslack = XDR_QUADLEN(len) + 2;
 922                break;
 923        case RPC_GSS_SVC_INTEGRITY:
 924                /* verifier data, flavor, length, length, sequence number: */
 925                task->tk_auth->au_rslack = XDR_QUADLEN(len) + 4;
 926                break;
 927        case RPC_GSS_SVC_PRIVACY:
 928                goto out_bad;
 929        }
 930         gss_put_ctx(ctx);
 931         dprintk("RPC: %4u GSS gss_validate: gss_verify_mic succeeded.\n",
 932                         task->tk_pid);
 933         return p + XDR_QUADLEN(len);
 934 out_bad:
 935         gss_put_ctx(ctx);
 936         dprintk("RPC: %4u gss_validate failed.\n", task->tk_pid);
 937         return NULL;
 938 }
 939
 940 static inline int
 941 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 942                 kxdrproc_t encode, struct rpc_rqst *rqstp, u32 *p, void *obj)
 943 {
 944         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
 945         struct xdr_buf  integ_buf;
 946         u32             *integ_len = NULL;
 947         struct xdr_netobj mic;
 948         u32             offset, *q;
 949         struct kvec     *iov;
 950         u32             maj_stat = 0;
 951         int             status = -EIO;
 952
 953         integ_len = p++;
 954         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 955         *p++ = htonl(rqstp->rq_seqno);
 956
 957         status = encode(rqstp, p, obj);
 958         if (status)
 959                 return status;
 960
 961         if (xdr_buf_subsegment(snd_buf, &integ_buf,
 962                                 offset, snd_buf->len - offset))
 963                 return status;
 964         *integ_len = htonl(integ_buf.len);
 965
 966         /* guess whether we're in the head or the tail: */
 967         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
 968                 iov = snd_buf->tail;
 969         else
 970                 iov = snd_buf->head;
 971         p = iov->iov_base + iov->iov_len;
 972         mic.data = (u8 *)(p + 1);
 973
 974         maj_stat = gss_get_mic(ctx->gc_gss_ctx,
 975                         GSS_C_QOP_DEFAULT, &integ_buf, &mic);
 976         status = -EIO; /* XXX? */
 977         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 978                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 979         else if (maj_stat)
 980                 return status;
 981         q = xdr_encode_opaque(p, NULL, mic.len);
 982
 983         offset = (u8 *)q - (u8 *)p;
 984         iov->iov_len += offset;
 985         snd_buf->len += offset;
 986         return 0;
 987 }
 988
 989 static int
 990 gss_wrap_req(struct rpc_task *task,
 991              kxdrproc_t encode, void *rqstp, u32 *p, void *obj)
 992 {
 993         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 994         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 995                         gc_base);
 996         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 997         int             status = -EIO;
 998
 999         dprintk("RPC: %4u gss_wrap_req\n", task->tk_pid);
1000         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1001                 /* The spec seems a little ambiguous here, but I think that not
1002                  * wrapping context destruction requests makes the most sense.
1003                  */
1004                 status = encode(rqstp, p, obj);
1005                 goto out;
1006         }
1007         switch (gss_cred->gc_service) {
1008                 case RPC_GSS_SVC_NONE:
1009                         status = encode(rqstp, p, obj);
1010                         break;
1011                 case RPC_GSS_SVC_INTEGRITY:
1012                         status = gss_wrap_req_integ(cred, ctx, encode,
1013                                                                 rqstp, p, obj);
1014                         break;
1015                 case RPC_GSS_SVC_PRIVACY:
1016                         break;
1017         }
1018 out:
1019         gss_put_ctx(ctx);
1020         dprintk("RPC: %4u gss_wrap_req returning %d\n", task->tk_pid, status);
1021         return status;
1022 }
1023
1024 static inline int
1025 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1026                 struct rpc_rqst *rqstp, u32 **p)
1027 {
1028         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1029         struct xdr_buf integ_buf;
1030         struct xdr_netobj mic;
1031         u32 data_offset, mic_offset;
1032         u32 integ_len;
1033         u32 maj_stat;
1034         int status = -EIO;
1035
1036         integ_len = ntohl(*(*p)++);
1037         if (integ_len & 3)
1038                 return status;
1039         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1040         mic_offset = integ_len + data_offset;
1041         if (mic_offset > rcv_buf->len)
1042                 return status;
1043         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1044                 return status;
1045
1046         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1047                                 mic_offset - data_offset))
1048                 return status;
1049
1050         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1051                 return status;
1052
1053         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf,
1054                         &mic, NULL);
1055         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1056                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
1057         if (maj_stat != GSS_S_COMPLETE)
1058                 return status;
1059         return 0;
1060 }
1061
1062 static int
1063 gss_unwrap_resp(struct rpc_task *task,
1064                 kxdrproc_t decode, void *rqstp, u32 *p, void *obj)
1065 {
1066         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1067         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1068                         gc_base);
1069         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1070         int             status = -EIO;
1071
1072         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1073                 goto out_decode;
1074         switch (gss_cred->gc_service) {
1075                 case RPC_GSS_SVC_NONE:
1076                         break;
1077                 case RPC_GSS_SVC_INTEGRITY:
1078                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1079                         if (status)
1080                                 goto out;
1081                         break;
1082                 case RPC_GSS_SVC_PRIVACY:
1083                         break;
1084         }
1085 out_decode:
1086         status = decode(rqstp, p, obj);
1087 out:
1088         gss_put_ctx(ctx);
1089         dprintk("RPC: %4u gss_unwrap_resp returning %d\n", task->tk_pid,
1090                         status);
1091         return status;
1092 }
1093
1094 static struct rpc_authops authgss_ops = {
1095         .owner          = THIS_MODULE,
1096         .au_flavor      = RPC_AUTH_GSS,
1097 #ifdef RPC_DEBUG
1098         .au_name        = "RPCSEC_GSS",
1099 #endif
1100         .create         = gss_create,
1101         .destroy        = gss_destroy,
1102         .lookup_cred    = gss_lookup_cred,
1103         .crcreate       = gss_create_cred
1104 };
1105
1106 static struct rpc_credops gss_credops = {
1107         .cr_name        = "AUTH_GSS",
1108         .crdestroy      = gss_destroy_cred,
1109         .crmatch        = gss_match,
1110         .crmarshal      = gss_marshal,
1111         .crrefresh      = gss_refresh,
1112         .crvalidate     = gss_validate,
1113         .crwrap_req     = gss_wrap_req,
1114         .crunwrap_resp  = gss_unwrap_resp,
1115 };
1116
1117 static struct rpc_pipe_ops gss_upcall_ops = {
1118         .upcall         = gss_pipe_upcall,
1119         .downcall       = gss_pipe_downcall,
1120         .destroy_msg    = gss_pipe_destroy_msg,
1121         .release_pipe   = gss_pipe_release,
1122 };
1123
1124 /*
1125  * Initialize RPCSEC_GSS module
1126  */
1127 static int __init init_rpcsec_gss(void)
1128 {
1129         int err = 0;
1130
1131         err = rpcauth_register(&authgss_ops);
1132         if (err)
1133                 goto out;
1134         err = gss_svc_init();
1135         if (err)
1136                 goto out_unregister;
1137         return 0;
1138 out_unregister:
1139         rpcauth_unregister(&authgss_ops);
1140 out:
1141         return err;
1142 }
1143
1144 static void __exit exit_rpcsec_gss(void)
1145 {
1146         gss_svc_shutdown();
1147         rpcauth_unregister(&authgss_ops);
1148 }
1149
1150 MODULE_LICENSE("GPL");
1151 module_init(init_rpcsec_gss)
1152 module_exit(exit_rpcsec_gss)