Pileus Git - ~andy/linux/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 #define GSS_RETRY_EXPIRED 5
  61 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  62
  63 #ifdef RPC_DEBUG
  64 # define RPCDBG_FACILITY        RPCDBG_AUTH
  65 #endif
  66
  67 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  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          100
  71
  72 struct gss_auth {
  73         struct kref kref;
  74         struct rpc_auth rpc_auth;
  75         struct gss_api_mech *mech;
  76         enum rpc_gss_svc service;
  77         struct rpc_clnt *client;
  78         /*
  79          * There are two upcall pipes; dentry[1], named "gssd", is used
  80          * for the new text-based upcall; dentry[0] is named after the
  81          * mechanism (for example, "krb5") and exists for
  82          * backwards-compatibility with older gssd's.
  83          */
  84         struct rpc_pipe *pipe[2];
  85 };
  86
  87 /* pipe_version >= 0 if and only if someone has a pipe open. */
  88 static int pipe_version = -1;
  89 static atomic_t pipe_users = ATOMIC_INIT(0);
  90 static DEFINE_SPINLOCK(pipe_version_lock);
  91 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
  92 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
  93
  94 static void gss_free_ctx(struct gss_cl_ctx *);
  95 static const struct rpc_pipe_ops gss_upcall_ops_v0;
  96 static const struct rpc_pipe_ops gss_upcall_ops_v1;
  97
  98 static inline struct gss_cl_ctx *
  99 gss_get_ctx(struct gss_cl_ctx *ctx)
 100 {
 101         atomic_inc(&ctx->count);
 102         return ctx;
 103 }
 104
 105 static inline void
 106 gss_put_ctx(struct gss_cl_ctx *ctx)
 107 {
 108         if (atomic_dec_and_test(&ctx->count))
 109                 gss_free_ctx(ctx);
 110 }
 111
 112 /* gss_cred_set_ctx:
 113  * called by gss_upcall_callback and gss_create_upcall in order
 114  * to set the gss context. The actual exchange of an old context
 115  * and a new one is protected by the pipe->lock.
 116  */
 117 static void
 118 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 119 {
 120         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 121
 122         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 123                 return;
 124         gss_get_ctx(ctx);
 125         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 126         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 127         smp_mb__before_clear_bit();
 128         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 129 }
 130
 131 static const void *
 132 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 133 {
 134         const void *q = (const void *)((const char *)p + len);
 135         if (unlikely(q > end || q < p))
 136                 return ERR_PTR(-EFAULT);
 137         memcpy(res, p, len);
 138         return q;
 139 }
 140
 141 static inline const void *
 142 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 143 {
 144         const void *q;
 145         unsigned int len;
 146
 147         p = simple_get_bytes(p, end, &len, sizeof(len));
 148         if (IS_ERR(p))
 149                 return p;
 150         q = (const void *)((const char *)p + len);
 151         if (unlikely(q > end || q < p))
 152                 return ERR_PTR(-EFAULT);
 153         dest->data = kmemdup(p, len, GFP_NOFS);
 154         if (unlikely(dest->data == NULL))
 155                 return ERR_PTR(-ENOMEM);
 156         dest->len = len;
 157         return q;
 158 }
 159
 160 static struct gss_cl_ctx *
 161 gss_cred_get_ctx(struct rpc_cred *cred)
 162 {
 163         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 164         struct gss_cl_ctx *ctx = NULL;
 165
 166         rcu_read_lock();
 167         if (gss_cred->gc_ctx)
 168                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 169         rcu_read_unlock();
 170         return ctx;
 171 }
 172
 173 static struct gss_cl_ctx *
 174 gss_alloc_context(void)
 175 {
 176         struct gss_cl_ctx *ctx;
 177
 178         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 179         if (ctx != NULL) {
 180                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 181                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 182                 spin_lock_init(&ctx->gc_seq_lock);
 183                 atomic_set(&ctx->count,1);
 184         }
 185         return ctx;
 186 }
 187
 188 #define GSSD_MIN_TIMEOUT (60 * 60)
 189 static const void *
 190 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 191 {
 192         const void *q;
 193         unsigned int seclen;
 194         unsigned int timeout;
 195         unsigned long now = jiffies;
 196         u32 window_size;
 197         int ret;
 198
 199         /* First unsigned int gives the remaining lifetime in seconds of the
 200          * credential - e.g. the remaining TGT lifetime for Kerberos or
 201          * the -t value passed to GSSD.
 202          */
 203         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 204         if (IS_ERR(p))
 205                 goto err;
 206         if (timeout == 0)
 207                 timeout = GSSD_MIN_TIMEOUT;
 208         ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
 209         /* Sequence number window. Determines the maximum number of
 210          * simultaneous requests
 211          */
 212         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 213         if (IS_ERR(p))
 214                 goto err;
 215         ctx->gc_win = window_size;
 216         /* gssd signals an error by passing ctx->gc_win = 0: */
 217         if (ctx->gc_win == 0) {
 218                 /*
 219                  * in which case, p points to an error code. Anything other
 220                  * than -EKEYEXPIRED gets converted to -EACCES.
 221                  */
 222                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 223                 if (!IS_ERR(p))
 224                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 225                                                     ERR_PTR(-EACCES);
 226                 goto err;
 227         }
 228         /* copy the opaque wire context */
 229         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 230         if (IS_ERR(p))
 231                 goto err;
 232         /* import the opaque security context */
 233         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 234         if (IS_ERR(p))
 235                 goto err;
 236         q = (const void *)((const char *)p + seclen);
 237         if (unlikely(q > end || q < p)) {
 238                 p = ERR_PTR(-EFAULT);
 239                 goto err;
 240         }
 241         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, GFP_NOFS);
 242         if (ret < 0) {
 243                 p = ERR_PTR(ret);
 244                 goto err;
 245         }
 246         dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u\n",
 247                 __func__, ctx->gc_expiry, now, timeout);
 248         return q;
 249 err:
 250         dprintk("RPC:       %s returns %ld gc_expiry %lu now %lu timeout %u\n",
 251                 __func__, -PTR_ERR(p), ctx->gc_expiry, now, timeout);
 252         return p;
 253 }
 254
 255 #define UPCALL_BUF_LEN 128
 256
 257 struct gss_upcall_msg {
 258         atomic_t count;
 259         kuid_t  uid;
 260         struct rpc_pipe_msg msg;
 261         struct list_head list;
 262         struct gss_auth *auth;
 263         struct rpc_pipe *pipe;
 264         struct rpc_wait_queue rpc_waitqueue;
 265         wait_queue_head_t waitqueue;
 266         struct gss_cl_ctx *ctx;
 267         char databuf[UPCALL_BUF_LEN];
 268 };
 269
 270 static int get_pipe_version(void)
 271 {
 272         int ret;
 273
 274         spin_lock(&pipe_version_lock);
 275         if (pipe_version >= 0) {
 276                 atomic_inc(&pipe_users);
 277                 ret = pipe_version;
 278         } else
 279                 ret = -EAGAIN;
 280         spin_unlock(&pipe_version_lock);
 281         return ret;
 282 }
 283
 284 static void put_pipe_version(void)
 285 {
 286         if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
 287                 pipe_version = -1;
 288                 spin_unlock(&pipe_version_lock);
 289         }
 290 }
 291
 292 static void
 293 gss_release_msg(struct gss_upcall_msg *gss_msg)
 294 {
 295         if (!atomic_dec_and_test(&gss_msg->count))
 296                 return;
 297         put_pipe_version();
 298         BUG_ON(!list_empty(&gss_msg->list));
 299         if (gss_msg->ctx != NULL)
 300                 gss_put_ctx(gss_msg->ctx);
 301         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 302         kfree(gss_msg);
 303 }
 304
 305 static struct gss_upcall_msg *
 306 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid)
 307 {
 308         struct gss_upcall_msg *pos;
 309         list_for_each_entry(pos, &pipe->in_downcall, list) {
 310                 if (!uid_eq(pos->uid, uid))
 311                         continue;
 312                 atomic_inc(&pos->count);
 313                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 314                 return pos;
 315         }
 316         dprintk("RPC:       %s found nothing\n", __func__);
 317         return NULL;
 318 }
 319
 320 /* Try to add an upcall to the pipefs queue.
 321  * If an upcall owned by our uid already exists, then we return a reference
 322  * to that upcall instead of adding the new upcall.
 323  */
 324 static inline struct gss_upcall_msg *
 325 gss_add_msg(struct gss_upcall_msg *gss_msg)
 326 {
 327         struct rpc_pipe *pipe = gss_msg->pipe;
 328         struct gss_upcall_msg *old;
 329
 330         spin_lock(&pipe->lock);
 331         old = __gss_find_upcall(pipe, gss_msg->uid);
 332         if (old == NULL) {
 333                 atomic_inc(&gss_msg->count);
 334                 list_add(&gss_msg->list, &pipe->in_downcall);
 335         } else
 336                 gss_msg = old;
 337         spin_unlock(&pipe->lock);
 338         return gss_msg;
 339 }
 340
 341 static void
 342 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 343 {
 344         list_del_init(&gss_msg->list);
 345         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 346         wake_up_all(&gss_msg->waitqueue);
 347         atomic_dec(&gss_msg->count);
 348 }
 349
 350 static void
 351 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 352 {
 353         struct rpc_pipe *pipe = gss_msg->pipe;
 354
 355         if (list_empty(&gss_msg->list))
 356                 return;
 357         spin_lock(&pipe->lock);
 358         if (!list_empty(&gss_msg->list))
 359                 __gss_unhash_msg(gss_msg);
 360         spin_unlock(&pipe->lock);
 361 }
 362
 363 static void
 364 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 365 {
 366         switch (gss_msg->msg.errno) {
 367         case 0:
 368                 if (gss_msg->ctx == NULL)
 369                         break;
 370                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 371                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 372                 break;
 373         case -EKEYEXPIRED:
 374                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 375         }
 376         gss_cred->gc_upcall_timestamp = jiffies;
 377         gss_cred->gc_upcall = NULL;
 378         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 379 }
 380
 381 static void
 382 gss_upcall_callback(struct rpc_task *task)
 383 {
 384         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 385                         struct gss_cred, gc_base);
 386         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 387         struct rpc_pipe *pipe = gss_msg->pipe;
 388
 389         spin_lock(&pipe->lock);
 390         gss_handle_downcall_result(gss_cred, gss_msg);
 391         spin_unlock(&pipe->lock);
 392         task->tk_status = gss_msg->msg.errno;
 393         gss_release_msg(gss_msg);
 394 }
 395
 396 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 397 {
 398         gss_msg->msg.data = &gss_msg->uid;
 399         gss_msg->msg.len = sizeof(gss_msg->uid);
 400 }
 401
 402 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 403                                 struct rpc_clnt *clnt,
 404                                 const char *service_name)
 405 {
 406         struct gss_api_mech *mech = gss_msg->auth->mech;
 407         char *p = gss_msg->databuf;
 408         int len = 0;
 409
 410         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
 411                                    mech->gm_name,
 412                                    gss_msg->uid);
 413         p += gss_msg->msg.len;
 414         if (clnt->cl_principal) {
 415                 len = sprintf(p, "target=%s ", clnt->cl_principal);
 416                 p += len;
 417                 gss_msg->msg.len += len;
 418         }
 419         if (service_name != NULL) {
 420                 len = sprintf(p, "service=%s ", service_name);
 421                 p += len;
 422                 gss_msg->msg.len += len;
 423         }
 424         if (mech->gm_upcall_enctypes) {
 425                 len = sprintf(p, "enctypes=%s ", mech->gm_upcall_enctypes);
 426                 p += len;
 427                 gss_msg->msg.len += len;
 428         }
 429         len = sprintf(p, "\n");
 430         gss_msg->msg.len += len;
 431
 432         gss_msg->msg.data = gss_msg->databuf;
 433         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
 434 }
 435
 436 static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
 437                                 struct rpc_clnt *clnt,
 438                                 const char *service_name)
 439 {
 440         if (pipe_version == 0)
 441                 gss_encode_v0_msg(gss_msg);
 442         else /* pipe_version == 1 */
 443                 gss_encode_v1_msg(gss_msg, clnt, service_name);
 444 }
 445
 446 static struct gss_upcall_msg *
 447 gss_alloc_msg(struct gss_auth *gss_auth, struct rpc_clnt *clnt,
 448                 kuid_t uid, const char *service_name)
 449 {
 450         struct gss_upcall_msg *gss_msg;
 451         int vers;
 452
 453         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 454         if (gss_msg == NULL)
 455                 return ERR_PTR(-ENOMEM);
 456         vers = get_pipe_version();
 457         if (vers < 0) {
 458                 kfree(gss_msg);
 459                 return ERR_PTR(vers);
 460         }
 461         gss_msg->pipe = gss_auth->pipe[vers];
 462         INIT_LIST_HEAD(&gss_msg->list);
 463         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 464         init_waitqueue_head(&gss_msg->waitqueue);
 465         atomic_set(&gss_msg->count, 1);
 466         gss_msg->uid = uid;
 467         gss_msg->auth = gss_auth;
 468         gss_encode_msg(gss_msg, clnt, service_name);
 469         return gss_msg;
 470 }
 471
 472 static struct gss_upcall_msg *
 473 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 474 {
 475         struct gss_cred *gss_cred = container_of(cred,
 476                         struct gss_cred, gc_base);
 477         struct gss_upcall_msg *gss_new, *gss_msg;
 478         kuid_t uid = cred->cr_uid;
 479
 480         gss_new = gss_alloc_msg(gss_auth, clnt, uid, gss_cred->gc_principal);
 481         if (IS_ERR(gss_new))
 482                 return gss_new;
 483         gss_msg = gss_add_msg(gss_new);
 484         if (gss_msg == gss_new) {
 485                 int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 486                 if (res) {
 487                         gss_unhash_msg(gss_new);
 488                         gss_msg = ERR_PTR(res);
 489                 }
 490         } else
 491                 gss_release_msg(gss_new);
 492         return gss_msg;
 493 }
 494
 495 static void warn_gssd(void)
 496 {
 497         static unsigned long ratelimit;
 498         unsigned long now = jiffies;
 499
 500         if (time_after(now, ratelimit)) {
 501                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 502                                 "Please check user daemon is running.\n");
 503                 ratelimit = now + 15*HZ;
 504         }
 505 }
 506
 507 static inline int
 508 gss_refresh_upcall(struct rpc_task *task)
 509 {
 510         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 511         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 512                         struct gss_auth, rpc_auth);
 513         struct gss_cred *gss_cred = container_of(cred,
 514                         struct gss_cred, gc_base);
 515         struct gss_upcall_msg *gss_msg;
 516         struct rpc_pipe *pipe;
 517         int err = 0;
 518
 519         dprintk("RPC: %5u %s for uid %u\n",
 520                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 521         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 522         if (PTR_ERR(gss_msg) == -EAGAIN) {
 523                 /* XXX: warning on the first, under the assumption we
 524                  * shouldn't normally hit this case on a refresh. */
 525                 warn_gssd();
 526                 task->tk_timeout = 15*HZ;
 527                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 528                 return -EAGAIN;
 529         }
 530         if (IS_ERR(gss_msg)) {
 531                 err = PTR_ERR(gss_msg);
 532                 goto out;
 533         }
 534         pipe = gss_msg->pipe;
 535         spin_lock(&pipe->lock);
 536         if (gss_cred->gc_upcall != NULL)
 537                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 538         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 539                 task->tk_timeout = 0;
 540                 gss_cred->gc_upcall = gss_msg;
 541                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 542                 atomic_inc(&gss_msg->count);
 543                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 544         } else {
 545                 gss_handle_downcall_result(gss_cred, gss_msg);
 546                 err = gss_msg->msg.errno;
 547         }
 548         spin_unlock(&pipe->lock);
 549         gss_release_msg(gss_msg);
 550 out:
 551         dprintk("RPC: %5u %s for uid %u result %d\n",
 552                 task->tk_pid, __func__,
 553                 from_kuid(&init_user_ns, cred->cr_uid), err);
 554         return err;
 555 }
 556
 557 static inline int
 558 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 559 {
 560         struct rpc_pipe *pipe;
 561         struct rpc_cred *cred = &gss_cred->gc_base;
 562         struct gss_upcall_msg *gss_msg;
 563         DEFINE_WAIT(wait);
 564         int err = 0;
 565
 566         dprintk("RPC:       %s for uid %u\n",
 567                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 568 retry:
 569         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 570         if (PTR_ERR(gss_msg) == -EAGAIN) {
 571                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 572                                 pipe_version >= 0, 15*HZ);
 573                 if (pipe_version < 0) {
 574                         warn_gssd();
 575                         err = -EACCES;
 576                 }
 577                 if (err)
 578                         goto out;
 579                 goto retry;
 580         }
 581         if (IS_ERR(gss_msg)) {
 582                 err = PTR_ERR(gss_msg);
 583                 goto out;
 584         }
 585         pipe = gss_msg->pipe;
 586         for (;;) {
 587                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 588                 spin_lock(&pipe->lock);
 589                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 590                         break;
 591                 }
 592                 spin_unlock(&pipe->lock);
 593                 if (fatal_signal_pending(current)) {
 594                         err = -ERESTARTSYS;
 595                         goto out_intr;
 596                 }
 597                 schedule();
 598         }
 599         if (gss_msg->ctx)
 600                 gss_cred_set_ctx(cred, gss_msg->ctx);
 601         else
 602                 err = gss_msg->msg.errno;
 603         spin_unlock(&pipe->lock);
 604 out_intr:
 605         finish_wait(&gss_msg->waitqueue, &wait);
 606         gss_release_msg(gss_msg);
 607 out:
 608         dprintk("RPC:       %s for uid %u result %d\n",
 609                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 610         return err;
 611 }
 612
 613 #define MSG_BUF_MAXSIZE 1024
 614
 615 static ssize_t
 616 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 617 {
 618         const void *p, *end;
 619         void *buf;
 620         struct gss_upcall_msg *gss_msg;
 621         struct rpc_pipe *pipe = RPC_I(filp->f_dentry->d_inode)->pipe;
 622         struct gss_cl_ctx *ctx;
 623         uid_t uid;
 624         ssize_t err = -EFBIG;
 625
 626         if (mlen > MSG_BUF_MAXSIZE)
 627                 goto out;
 628         err = -ENOMEM;
 629         buf = kmalloc(mlen, GFP_NOFS);
 630         if (!buf)
 631                 goto out;
 632
 633         err = -EFAULT;
 634         if (copy_from_user(buf, src, mlen))
 635                 goto err;
 636
 637         end = (const void *)((char *)buf + mlen);
 638         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 639         if (IS_ERR(p)) {
 640                 err = PTR_ERR(p);
 641                 goto err;
 642         }
 643
 644         err = -ENOMEM;
 645         ctx = gss_alloc_context();
 646         if (ctx == NULL)
 647                 goto err;
 648
 649         err = -ENOENT;
 650         /* Find a matching upcall */
 651         spin_lock(&pipe->lock);
 652         gss_msg = __gss_find_upcall(pipe, uid);
 653         if (gss_msg == NULL) {
 654                 spin_unlock(&pipe->lock);
 655                 goto err_put_ctx;
 656         }
 657         list_del_init(&gss_msg->list);
 658         spin_unlock(&pipe->lock);
 659
 660         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 661         if (IS_ERR(p)) {
 662                 err = PTR_ERR(p);
 663                 switch (err) {
 664                 case -EACCES:
 665                 case -EKEYEXPIRED:
 666                         gss_msg->msg.errno = err;
 667                         err = mlen;
 668                         break;
 669                 case -EFAULT:
 670                 case -ENOMEM:
 671                 case -EINVAL:
 672                 case -ENOSYS:
 673                         gss_msg->msg.errno = -EAGAIN;
 674                         break;
 675                 default:
 676                         printk(KERN_CRIT "%s: bad return from "
 677                                 "gss_fill_context: %zd\n", __func__, err);
 678                         BUG();
 679                 }
 680                 goto err_release_msg;
 681         }
 682         gss_msg->ctx = gss_get_ctx(ctx);
 683         err = mlen;
 684
 685 err_release_msg:
 686         spin_lock(&pipe->lock);
 687         __gss_unhash_msg(gss_msg);
 688         spin_unlock(&pipe->lock);
 689         gss_release_msg(gss_msg);
 690 err_put_ctx:
 691         gss_put_ctx(ctx);
 692 err:
 693         kfree(buf);
 694 out:
 695         dprintk("RPC:       %s returning %Zd\n", __func__, err);
 696         return err;
 697 }
 698
 699 static int gss_pipe_open(struct inode *inode, int new_version)
 700 {
 701         int ret = 0;
 702
 703         spin_lock(&pipe_version_lock);
 704         if (pipe_version < 0) {
 705                 /* First open of any gss pipe determines the version: */
 706                 pipe_version = new_version;
 707                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 708                 wake_up(&pipe_version_waitqueue);
 709         } else if (pipe_version != new_version) {
 710                 /* Trying to open a pipe of a different version */
 711                 ret = -EBUSY;
 712                 goto out;
 713         }
 714         atomic_inc(&pipe_users);
 715 out:
 716         spin_unlock(&pipe_version_lock);
 717         return ret;
 718
 719 }
 720
 721 static int gss_pipe_open_v0(struct inode *inode)
 722 {
 723         return gss_pipe_open(inode, 0);
 724 }
 725
 726 static int gss_pipe_open_v1(struct inode *inode)
 727 {
 728         return gss_pipe_open(inode, 1);
 729 }
 730
 731 static void
 732 gss_pipe_release(struct inode *inode)
 733 {
 734         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 735         struct gss_upcall_msg *gss_msg;
 736
 737 restart:
 738         spin_lock(&pipe->lock);
 739         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 740
 741                 if (!list_empty(&gss_msg->msg.list))
 742                         continue;
 743                 gss_msg->msg.errno = -EPIPE;
 744                 atomic_inc(&gss_msg->count);
 745                 __gss_unhash_msg(gss_msg);
 746                 spin_unlock(&pipe->lock);
 747                 gss_release_msg(gss_msg);
 748                 goto restart;
 749         }
 750         spin_unlock(&pipe->lock);
 751
 752         put_pipe_version();
 753 }
 754
 755 static void
 756 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 757 {
 758         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 759
 760         if (msg->errno < 0) {
 761                 dprintk("RPC:       %s releasing msg %p\n",
 762                         __func__, gss_msg);
 763                 atomic_inc(&gss_msg->count);
 764                 gss_unhash_msg(gss_msg);
 765                 if (msg->errno == -ETIMEDOUT)
 766                         warn_gssd();
 767                 gss_release_msg(gss_msg);
 768         }
 769 }
 770
 771 static void gss_pipes_dentries_destroy(struct rpc_auth *auth)
 772 {
 773         struct gss_auth *gss_auth;
 774
 775         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 776         if (gss_auth->pipe[0]->dentry)
 777                 rpc_unlink(gss_auth->pipe[0]->dentry);
 778         if (gss_auth->pipe[1]->dentry)
 779                 rpc_unlink(gss_auth->pipe[1]->dentry);
 780 }
 781
 782 static int gss_pipes_dentries_create(struct rpc_auth *auth)
 783 {
 784         int err;
 785         struct gss_auth *gss_auth;
 786         struct rpc_clnt *clnt;
 787
 788         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 789         clnt = gss_auth->client;
 790
 791         gss_auth->pipe[1]->dentry = rpc_mkpipe_dentry(clnt->cl_dentry,
 792                                                       "gssd",
 793                                                       clnt, gss_auth->pipe[1]);
 794         if (IS_ERR(gss_auth->pipe[1]->dentry))
 795                 return PTR_ERR(gss_auth->pipe[1]->dentry);
 796         gss_auth->pipe[0]->dentry = rpc_mkpipe_dentry(clnt->cl_dentry,
 797                                                       gss_auth->mech->gm_name,
 798                                                       clnt, gss_auth->pipe[0]);
 799         if (IS_ERR(gss_auth->pipe[0]->dentry)) {
 800                 err = PTR_ERR(gss_auth->pipe[0]->dentry);
 801                 goto err_unlink_pipe_1;
 802         }
 803         return 0;
 804
 805 err_unlink_pipe_1:
 806         rpc_unlink(gss_auth->pipe[1]->dentry);
 807         return err;
 808 }
 809
 810 static void gss_pipes_dentries_destroy_net(struct rpc_clnt *clnt,
 811                                            struct rpc_auth *auth)
 812 {
 813         struct net *net = rpc_net_ns(clnt);
 814         struct super_block *sb;
 815
 816         sb = rpc_get_sb_net(net);
 817         if (sb) {
 818                 if (clnt->cl_dentry)
 819                         gss_pipes_dentries_destroy(auth);
 820                 rpc_put_sb_net(net);
 821         }
 822 }
 823
 824 static int gss_pipes_dentries_create_net(struct rpc_clnt *clnt,
 825                                          struct rpc_auth *auth)
 826 {
 827         struct net *net = rpc_net_ns(clnt);
 828         struct super_block *sb;
 829         int err = 0;
 830
 831         sb = rpc_get_sb_net(net);
 832         if (sb) {
 833                 if (clnt->cl_dentry)
 834                         err = gss_pipes_dentries_create(auth);
 835                 rpc_put_sb_net(net);
 836         }
 837         return err;
 838 }
 839
 840 /*
 841  * NOTE: we have the opportunity to use different
 842  * parameters based on the input flavor (which must be a pseudoflavor)
 843  */
 844 static struct rpc_auth *
 845 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 846 {
 847         struct gss_auth *gss_auth;
 848         struct rpc_auth * auth;
 849         int err = -ENOMEM; /* XXX? */
 850
 851         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 852
 853         if (!try_module_get(THIS_MODULE))
 854                 return ERR_PTR(err);
 855         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 856                 goto out_dec;
 857         gss_auth->client = clnt;
 858         err = -EINVAL;
 859         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 860         if (!gss_auth->mech) {
 861                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 862                                 __func__, flavor);
 863                 goto err_free;
 864         }
 865         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 866         if (gss_auth->service == 0)
 867                 goto err_put_mech;
 868         auth = &gss_auth->rpc_auth;
 869         auth->au_cslack = GSS_CRED_SLACK >> 2;
 870         auth->au_rslack = GSS_VERF_SLACK >> 2;
 871         auth->au_ops = &authgss_ops;
 872         auth->au_flavor = flavor;
 873         atomic_set(&auth->au_count, 1);
 874         kref_init(&gss_auth->kref);
 875
 876         /*
 877          * Note: if we created the old pipe first, then someone who
 878          * examined the directory at the right moment might conclude
 879          * that we supported only the old pipe.  So we instead create
 880          * the new pipe first.
 881          */
 882         gss_auth->pipe[1] = rpc_mkpipe_data(&gss_upcall_ops_v1,
 883                                             RPC_PIPE_WAIT_FOR_OPEN);
 884         if (IS_ERR(gss_auth->pipe[1])) {
 885                 err = PTR_ERR(gss_auth->pipe[1]);
 886                 goto err_put_mech;
 887         }
 888
 889         gss_auth->pipe[0] = rpc_mkpipe_data(&gss_upcall_ops_v0,
 890                                             RPC_PIPE_WAIT_FOR_OPEN);
 891         if (IS_ERR(gss_auth->pipe[0])) {
 892                 err = PTR_ERR(gss_auth->pipe[0]);
 893                 goto err_destroy_pipe_1;
 894         }
 895         err = gss_pipes_dentries_create_net(clnt, auth);
 896         if (err)
 897                 goto err_destroy_pipe_0;
 898         err = rpcauth_init_credcache(auth);
 899         if (err)
 900                 goto err_unlink_pipes;
 901
 902         return auth;
 903 err_unlink_pipes:
 904         gss_pipes_dentries_destroy_net(clnt, auth);
 905 err_destroy_pipe_0:
 906         rpc_destroy_pipe_data(gss_auth->pipe[0]);
 907 err_destroy_pipe_1:
 908         rpc_destroy_pipe_data(gss_auth->pipe[1]);
 909 err_put_mech:
 910         gss_mech_put(gss_auth->mech);
 911 err_free:
 912         kfree(gss_auth);
 913 out_dec:
 914         module_put(THIS_MODULE);
 915         return ERR_PTR(err);
 916 }
 917
 918 static void
 919 gss_free(struct gss_auth *gss_auth)
 920 {
 921         gss_pipes_dentries_destroy_net(gss_auth->client, &gss_auth->rpc_auth);
 922         rpc_destroy_pipe_data(gss_auth->pipe[0]);
 923         rpc_destroy_pipe_data(gss_auth->pipe[1]);
 924         gss_mech_put(gss_auth->mech);
 925
 926         kfree(gss_auth);
 927         module_put(THIS_MODULE);
 928 }
 929
 930 static void
 931 gss_free_callback(struct kref *kref)
 932 {
 933         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 934
 935         gss_free(gss_auth);
 936 }
 937
 938 static void
 939 gss_destroy(struct rpc_auth *auth)
 940 {
 941         struct gss_auth *gss_auth;
 942
 943         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 944                         auth, auth->au_flavor);
 945
 946         rpcauth_destroy_credcache(auth);
 947
 948         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 949         kref_put(&gss_auth->kref, gss_free_callback);
 950 }
 951
 952 /*
 953  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 954  * to the server with the GSS control procedure field set to
 955  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 956  * all RPCSEC_GSS state associated with that context.
 957  */
 958 static int
 959 gss_destroying_context(struct rpc_cred *cred)
 960 {
 961         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 962         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 963         struct rpc_task *task;
 964
 965         if (gss_cred->gc_ctx == NULL ||
 966             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 967                 return 0;
 968
 969         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 970         cred->cr_ops = &gss_nullops;
 971
 972         /* Take a reference to ensure the cred will be destroyed either
 973          * by the RPC call or by the put_rpccred() below */
 974         get_rpccred(cred);
 975
 976         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 977         if (!IS_ERR(task))
 978                 rpc_put_task(task);
 979
 980         put_rpccred(cred);
 981         return 1;
 982 }
 983
 984 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 985  * to create a new cred or context, so they check that things have been
 986  * allocated before freeing them. */
 987 static void
 988 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 989 {
 990         dprintk("RPC:       %s\n", __func__);
 991
 992         gss_delete_sec_context(&ctx->gc_gss_ctx);
 993         kfree(ctx->gc_wire_ctx.data);
 994         kfree(ctx);
 995 }
 996
 997 static void
 998 gss_free_ctx_callback(struct rcu_head *head)
 999 {
1000         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1001         gss_do_free_ctx(ctx);
1002 }
1003
1004 static void
1005 gss_free_ctx(struct gss_cl_ctx *ctx)
1006 {
1007         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1008 }
1009
1010 static void
1011 gss_free_cred(struct gss_cred *gss_cred)
1012 {
1013         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1014         kfree(gss_cred);
1015 }
1016
1017 static void
1018 gss_free_cred_callback(struct rcu_head *head)
1019 {
1020         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1021         gss_free_cred(gss_cred);
1022 }
1023
1024 static void
1025 gss_destroy_nullcred(struct rpc_cred *cred)
1026 {
1027         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1028         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1029         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
1030
1031         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1032         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1033         if (ctx)
1034                 gss_put_ctx(ctx);
1035         kref_put(&gss_auth->kref, gss_free_callback);
1036 }
1037
1038 static void
1039 gss_destroy_cred(struct rpc_cred *cred)
1040 {
1041
1042         if (gss_destroying_context(cred))
1043                 return;
1044         gss_destroy_nullcred(cred);
1045 }
1046
1047 /*
1048  * Lookup RPCSEC_GSS cred for the current process
1049  */
1050 static struct rpc_cred *
1051 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1052 {
1053         return rpcauth_lookup_credcache(auth, acred, flags);
1054 }
1055
1056 static struct rpc_cred *
1057 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1058 {
1059         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1060         struct gss_cred *cred = NULL;
1061         int err = -ENOMEM;
1062
1063         dprintk("RPC:       %s for uid %d, flavor %d\n",
1064                 __func__, from_kuid(&init_user_ns, acred->uid),
1065                 auth->au_flavor);
1066
1067         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1068                 goto out_err;
1069
1070         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1071         /*
1072          * Note: in order to force a call to call_refresh(), we deliberately
1073          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1074          */
1075         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1076         cred->gc_service = gss_auth->service;
1077         cred->gc_principal = NULL;
1078         if (acred->machine_cred)
1079                 cred->gc_principal = acred->principal;
1080         kref_get(&gss_auth->kref);
1081         return &cred->gc_base;
1082
1083 out_err:
1084         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1085         return ERR_PTR(err);
1086 }
1087
1088 static int
1089 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1090 {
1091         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1092         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1093         int err;
1094
1095         do {
1096                 err = gss_create_upcall(gss_auth, gss_cred);
1097         } while (err == -EAGAIN);
1098         return err;
1099 }
1100
1101 static int
1102 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1103 {
1104         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1105
1106         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1107                 goto out;
1108         /* Don't match with creds that have expired. */
1109         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1110                 return 0;
1111         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1112                 return 0;
1113 out:
1114         if (acred->principal != NULL) {
1115                 if (gss_cred->gc_principal == NULL)
1116                         return 0;
1117                 return strcmp(acred->principal, gss_cred->gc_principal) == 0;
1118         }
1119         if (gss_cred->gc_principal != NULL)
1120                 return 0;
1121         return uid_eq(rc->cr_uid, acred->uid);
1122 }
1123
1124 /*
1125 * Marshal credentials.
1126 * Maybe we should keep a cached credential for performance reasons.
1127 */
1128 static __be32 *
1129 gss_marshal(struct rpc_task *task, __be32 *p)
1130 {
1131         struct rpc_rqst *req = task->tk_rqstp;
1132         struct rpc_cred *cred = req->rq_cred;
1133         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1134                                                  gc_base);
1135         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1136         __be32          *cred_len;
1137         u32             maj_stat = 0;
1138         struct xdr_netobj mic;
1139         struct kvec     iov;
1140         struct xdr_buf  verf_buf;
1141
1142         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1143
1144         *p++ = htonl(RPC_AUTH_GSS);
1145         cred_len = p++;
1146
1147         spin_lock(&ctx->gc_seq_lock);
1148         req->rq_seqno = ctx->gc_seq++;
1149         spin_unlock(&ctx->gc_seq_lock);
1150
1151         *p++ = htonl((u32) RPC_GSS_VERSION);
1152         *p++ = htonl((u32) ctx->gc_proc);
1153         *p++ = htonl((u32) req->rq_seqno);
1154         *p++ = htonl((u32) gss_cred->gc_service);
1155         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1156         *cred_len = htonl((p - (cred_len + 1)) << 2);
1157
1158         /* We compute the checksum for the verifier over the xdr-encoded bytes
1159          * starting with the xid and ending at the end of the credential: */
1160         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
1161                                         req->rq_snd_buf.head[0].iov_base);
1162         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1163         xdr_buf_from_iov(&iov, &verf_buf);
1164
1165         /* set verifier flavor*/
1166         *p++ = htonl(RPC_AUTH_GSS);
1167
1168         mic.data = (u8 *)(p + 1);
1169         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1170         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1171                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1172         } else if (maj_stat != 0) {
1173                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1174                 goto out_put_ctx;
1175         }
1176         p = xdr_encode_opaque(p, NULL, mic.len);
1177         gss_put_ctx(ctx);
1178         return p;
1179 out_put_ctx:
1180         gss_put_ctx(ctx);
1181         return NULL;
1182 }
1183
1184 static int gss_renew_cred(struct rpc_task *task)
1185 {
1186         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1187         struct gss_cred *gss_cred = container_of(oldcred,
1188                                                  struct gss_cred,
1189                                                  gc_base);
1190         struct rpc_auth *auth = oldcred->cr_auth;
1191         struct auth_cred acred = {
1192                 .uid = oldcred->cr_uid,
1193                 .principal = gss_cred->gc_principal,
1194                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1195         };
1196         struct rpc_cred *new;
1197
1198         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1199         if (IS_ERR(new))
1200                 return PTR_ERR(new);
1201         task->tk_rqstp->rq_cred = new;
1202         put_rpccred(oldcred);
1203         return 0;
1204 }
1205
1206 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1207 {
1208         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1209                 unsigned long now = jiffies;
1210                 unsigned long begin, expire;
1211                 struct gss_cred *gss_cred;
1212
1213                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1214                 begin = gss_cred->gc_upcall_timestamp;
1215                 expire = begin + gss_expired_cred_retry_delay * HZ;
1216
1217                 if (time_in_range_open(now, begin, expire))
1218                         return 1;
1219         }
1220         return 0;
1221 }
1222
1223 /*
1224 * Refresh credentials. XXX - finish
1225 */
1226 static int
1227 gss_refresh(struct rpc_task *task)
1228 {
1229         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1230         int ret = 0;
1231
1232         if (gss_cred_is_negative_entry(cred))
1233                 return -EKEYEXPIRED;
1234
1235         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1236                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1237                 ret = gss_renew_cred(task);
1238                 if (ret < 0)
1239                         goto out;
1240                 cred = task->tk_rqstp->rq_cred;
1241         }
1242
1243         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1244                 ret = gss_refresh_upcall(task);
1245 out:
1246         return ret;
1247 }
1248
1249 /* Dummy refresh routine: used only when destroying the context */
1250 static int
1251 gss_refresh_null(struct rpc_task *task)
1252 {
1253         return -EACCES;
1254 }
1255
1256 static __be32 *
1257 gss_validate(struct rpc_task *task, __be32 *p)
1258 {
1259         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1260         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1261         __be32          seq;
1262         struct kvec     iov;
1263         struct xdr_buf  verf_buf;
1264         struct xdr_netobj mic;
1265         u32             flav,len;
1266         u32             maj_stat;
1267
1268         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1269
1270         flav = ntohl(*p++);
1271         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1272                 goto out_bad;
1273         if (flav != RPC_AUTH_GSS)
1274                 goto out_bad;
1275         seq = htonl(task->tk_rqstp->rq_seqno);
1276         iov.iov_base = &seq;
1277         iov.iov_len = sizeof(seq);
1278         xdr_buf_from_iov(&iov, &verf_buf);
1279         mic.data = (u8 *)p;
1280         mic.len = len;
1281
1282         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1283         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1284                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1285         if (maj_stat) {
1286                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1287                         task->tk_pid, __func__, maj_stat);
1288                 goto out_bad;
1289         }
1290         /* We leave it to unwrap to calculate au_rslack. For now we just
1291          * calculate the length of the verifier: */
1292         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1293         gss_put_ctx(ctx);
1294         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1295                         task->tk_pid, __func__);
1296         return p + XDR_QUADLEN(len);
1297 out_bad:
1298         gss_put_ctx(ctx);
1299         dprintk("RPC: %5u %s failed.\n", task->tk_pid, __func__);
1300         return NULL;
1301 }
1302
1303 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1304                                 __be32 *p, void *obj)
1305 {
1306         struct xdr_stream xdr;
1307
1308         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1309         encode(rqstp, &xdr, obj);
1310 }
1311
1312 static inline int
1313 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1314                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1315                    __be32 *p, void *obj)
1316 {
1317         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1318         struct xdr_buf  integ_buf;
1319         __be32          *integ_len = NULL;
1320         struct xdr_netobj mic;
1321         u32             offset;
1322         __be32          *q;
1323         struct kvec     *iov;
1324         u32             maj_stat = 0;
1325         int             status = -EIO;
1326
1327         integ_len = p++;
1328         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1329         *p++ = htonl(rqstp->rq_seqno);
1330
1331         gss_wrap_req_encode(encode, rqstp, p, obj);
1332
1333         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1334                                 offset, snd_buf->len - offset))
1335                 return status;
1336         *integ_len = htonl(integ_buf.len);
1337
1338         /* guess whether we're in the head or the tail: */
1339         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1340                 iov = snd_buf->tail;
1341         else
1342                 iov = snd_buf->head;
1343         p = iov->iov_base + iov->iov_len;
1344         mic.data = (u8 *)(p + 1);
1345
1346         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1347         status = -EIO; /* XXX? */
1348         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1349                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1350         else if (maj_stat)
1351                 return status;
1352         q = xdr_encode_opaque(p, NULL, mic.len);
1353
1354         offset = (u8 *)q - (u8 *)p;
1355         iov->iov_len += offset;
1356         snd_buf->len += offset;
1357         return 0;
1358 }
1359
1360 static void
1361 priv_release_snd_buf(struct rpc_rqst *rqstp)
1362 {
1363         int i;
1364
1365         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1366                 __free_page(rqstp->rq_enc_pages[i]);
1367         kfree(rqstp->rq_enc_pages);
1368 }
1369
1370 static int
1371 alloc_enc_pages(struct rpc_rqst *rqstp)
1372 {
1373         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1374         int first, last, i;
1375
1376         if (snd_buf->page_len == 0) {
1377                 rqstp->rq_enc_pages_num = 0;
1378                 return 0;
1379         }
1380
1381         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1382         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1383         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1384         rqstp->rq_enc_pages
1385                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1386                                 GFP_NOFS);
1387         if (!rqstp->rq_enc_pages)
1388                 goto out;
1389         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1390                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1391                 if (rqstp->rq_enc_pages[i] == NULL)
1392                         goto out_free;
1393         }
1394         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1395         return 0;
1396 out_free:
1397         rqstp->rq_enc_pages_num = i;
1398         priv_release_snd_buf(rqstp);
1399 out:
1400         return -EAGAIN;
1401 }
1402
1403 static inline int
1404 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1405                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1406                   __be32 *p, void *obj)
1407 {
1408         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1409         u32             offset;
1410         u32             maj_stat;
1411         int             status;
1412         __be32          *opaque_len;
1413         struct page     **inpages;
1414         int             first;
1415         int             pad;
1416         struct kvec     *iov;
1417         char            *tmp;
1418
1419         opaque_len = p++;
1420         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1421         *p++ = htonl(rqstp->rq_seqno);
1422
1423         gss_wrap_req_encode(encode, rqstp, p, obj);
1424
1425         status = alloc_enc_pages(rqstp);
1426         if (status)
1427                 return status;
1428         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1429         inpages = snd_buf->pages + first;
1430         snd_buf->pages = rqstp->rq_enc_pages;
1431         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1432         /*
1433          * Give the tail its own page, in case we need extra space in the
1434          * head when wrapping:
1435          *
1436          * call_allocate() allocates twice the slack space required
1437          * by the authentication flavor to rq_callsize.
1438          * For GSS, slack is GSS_CRED_SLACK.
1439          */
1440         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1441                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1442                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1443                 snd_buf->tail[0].iov_base = tmp;
1444         }
1445         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1446         /* slack space should prevent this ever happening: */
1447         BUG_ON(snd_buf->len > snd_buf->buflen);
1448         status = -EIO;
1449         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1450          * done anyway, so it's safe to put the request on the wire: */
1451         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1452                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1453         else if (maj_stat)
1454                 return status;
1455
1456         *opaque_len = htonl(snd_buf->len - offset);
1457         /* guess whether we're in the head or the tail: */
1458         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1459                 iov = snd_buf->tail;
1460         else
1461                 iov = snd_buf->head;
1462         p = iov->iov_base + iov->iov_len;
1463         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1464         memset(p, 0, pad);
1465         iov->iov_len += pad;
1466         snd_buf->len += pad;
1467
1468         return 0;
1469 }
1470
1471 static int
1472 gss_wrap_req(struct rpc_task *task,
1473              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1474 {
1475         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1476         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1477                         gc_base);
1478         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1479         int             status = -EIO;
1480
1481         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1482         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1483                 /* The spec seems a little ambiguous here, but I think that not
1484                  * wrapping context destruction requests makes the most sense.
1485                  */
1486                 gss_wrap_req_encode(encode, rqstp, p, obj);
1487                 status = 0;
1488                 goto out;
1489         }
1490         switch (gss_cred->gc_service) {
1491         case RPC_GSS_SVC_NONE:
1492                 gss_wrap_req_encode(encode, rqstp, p, obj);
1493                 status = 0;
1494                 break;
1495         case RPC_GSS_SVC_INTEGRITY:
1496                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1497                 break;
1498         case RPC_GSS_SVC_PRIVACY:
1499                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1500                 break;
1501         }
1502 out:
1503         gss_put_ctx(ctx);
1504         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1505         return status;
1506 }
1507
1508 static inline int
1509 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1510                 struct rpc_rqst *rqstp, __be32 **p)
1511 {
1512         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1513         struct xdr_buf integ_buf;
1514         struct xdr_netobj mic;
1515         u32 data_offset, mic_offset;
1516         u32 integ_len;
1517         u32 maj_stat;
1518         int status = -EIO;
1519
1520         integ_len = ntohl(*(*p)++);
1521         if (integ_len & 3)
1522                 return status;
1523         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1524         mic_offset = integ_len + data_offset;
1525         if (mic_offset > rcv_buf->len)
1526                 return status;
1527         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1528                 return status;
1529
1530         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1531                                 mic_offset - data_offset))
1532                 return status;
1533
1534         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1535                 return status;
1536
1537         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1538         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1539                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1540         if (maj_stat != GSS_S_COMPLETE)
1541                 return status;
1542         return 0;
1543 }
1544
1545 static inline int
1546 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1547                 struct rpc_rqst *rqstp, __be32 **p)
1548 {
1549         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1550         u32 offset;
1551         u32 opaque_len;
1552         u32 maj_stat;
1553         int status = -EIO;
1554
1555         opaque_len = ntohl(*(*p)++);
1556         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1557         if (offset + opaque_len > rcv_buf->len)
1558                 return status;
1559         /* remove padding: */
1560         rcv_buf->len = offset + opaque_len;
1561
1562         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1563         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1564                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1565         if (maj_stat != GSS_S_COMPLETE)
1566                 return status;
1567         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1568                 return status;
1569
1570         return 0;
1571 }
1572
1573 static int
1574 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1575                       __be32 *p, void *obj)
1576 {
1577         struct xdr_stream xdr;
1578
1579         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1580         return decode(rqstp, &xdr, obj);
1581 }
1582
1583 static int
1584 gss_unwrap_resp(struct rpc_task *task,
1585                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1586 {
1587         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1588         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1589                         gc_base);
1590         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1591         __be32          *savedp = p;
1592         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1593         int             savedlen = head->iov_len;
1594         int             status = -EIO;
1595
1596         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1597                 goto out_decode;
1598         switch (gss_cred->gc_service) {
1599         case RPC_GSS_SVC_NONE:
1600                 break;
1601         case RPC_GSS_SVC_INTEGRITY:
1602                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1603                 if (status)
1604                         goto out;
1605                 break;
1606         case RPC_GSS_SVC_PRIVACY:
1607                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1608                 if (status)
1609                         goto out;
1610                 break;
1611         }
1612         /* take into account extra slack for integrity and privacy cases: */
1613         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1614                                                 + (savedlen - head->iov_len);
1615 out_decode:
1616         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1617 out:
1618         gss_put_ctx(ctx);
1619         dprintk("RPC: %5u %s returning %d\n",
1620                 task->tk_pid, __func__, status);
1621         return status;
1622 }
1623
1624 static const struct rpc_authops authgss_ops = {
1625         .owner          = THIS_MODULE,
1626         .au_flavor      = RPC_AUTH_GSS,
1627         .au_name        = "RPCSEC_GSS",
1628         .create         = gss_create,
1629         .destroy        = gss_destroy,
1630         .lookup_cred    = gss_lookup_cred,
1631         .crcreate       = gss_create_cred,
1632         .pipes_create   = gss_pipes_dentries_create,
1633         .pipes_destroy  = gss_pipes_dentries_destroy,
1634         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1635 };
1636
1637 static const struct rpc_credops gss_credops = {
1638         .cr_name        = "AUTH_GSS",
1639         .crdestroy      = gss_destroy_cred,
1640         .cr_init        = gss_cred_init,
1641         .crbind         = rpcauth_generic_bind_cred,
1642         .crmatch        = gss_match,
1643         .crmarshal      = gss_marshal,
1644         .crrefresh      = gss_refresh,
1645         .crvalidate     = gss_validate,
1646         .crwrap_req     = gss_wrap_req,
1647         .crunwrap_resp  = gss_unwrap_resp,
1648 };
1649
1650 static const struct rpc_credops gss_nullops = {
1651         .cr_name        = "AUTH_GSS",
1652         .crdestroy      = gss_destroy_nullcred,
1653         .crbind         = rpcauth_generic_bind_cred,
1654         .crmatch        = gss_match,
1655         .crmarshal      = gss_marshal,
1656         .crrefresh      = gss_refresh_null,
1657         .crvalidate     = gss_validate,
1658         .crwrap_req     = gss_wrap_req,
1659         .crunwrap_resp  = gss_unwrap_resp,
1660 };
1661
1662 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1663         .upcall         = rpc_pipe_generic_upcall,
1664         .downcall       = gss_pipe_downcall,
1665         .destroy_msg    = gss_pipe_destroy_msg,
1666         .open_pipe      = gss_pipe_open_v0,
1667         .release_pipe   = gss_pipe_release,
1668 };
1669
1670 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1671         .upcall         = rpc_pipe_generic_upcall,
1672         .downcall       = gss_pipe_downcall,
1673         .destroy_msg    = gss_pipe_destroy_msg,
1674         .open_pipe      = gss_pipe_open_v1,
1675         .release_pipe   = gss_pipe_release,
1676 };
1677
1678 static __net_init int rpcsec_gss_init_net(struct net *net)
1679 {
1680         return gss_svc_init_net(net);
1681 }
1682
1683 static __net_exit void rpcsec_gss_exit_net(struct net *net)
1684 {
1685         gss_svc_shutdown_net(net);
1686 }
1687
1688 static struct pernet_operations rpcsec_gss_net_ops = {
1689         .init = rpcsec_gss_init_net,
1690         .exit = rpcsec_gss_exit_net,
1691 };
1692
1693 /*
1694  * Initialize RPCSEC_GSS module
1695  */
1696 static int __init init_rpcsec_gss(void)
1697 {
1698         int err = 0;
1699
1700         err = rpcauth_register(&authgss_ops);
1701         if (err)
1702                 goto out;
1703         err = gss_svc_init();
1704         if (err)
1705                 goto out_unregister;
1706         err = register_pernet_subsys(&rpcsec_gss_net_ops);
1707         if (err)
1708                 goto out_svc_exit;
1709         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1710         return 0;
1711 out_svc_exit:
1712         gss_svc_shutdown();
1713 out_unregister:
1714         rpcauth_unregister(&authgss_ops);
1715 out:
1716         return err;
1717 }
1718
1719 static void __exit exit_rpcsec_gss(void)
1720 {
1721         unregister_pernet_subsys(&rpcsec_gss_net_ops);
1722         gss_svc_shutdown();
1723         rpcauth_unregister(&authgss_ops);
1724         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1725 }
1726
1727 MODULE_LICENSE("GPL");
1728 module_param_named(expired_cred_retry_delay,
1729                    gss_expired_cred_retry_delay,
1730                    uint, 0644);
1731 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
1732                 "the RPC engine retries an expired credential");
1733
1734 module_init(init_rpcsec_gss)
1735 module_exit(exit_rpcsec_gss)