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 #include "../netns.h"
  56
  57 static const struct rpc_authops authgss_ops;
  58
  59 static const struct rpc_credops gss_credops;
  60 static const struct rpc_credops gss_nullops;
  61
  62 #define GSS_RETRY_EXPIRED 5
  63 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  64
  65 #ifdef RPC_DEBUG
  66 # define RPCDBG_FACILITY        RPCDBG_AUTH
  67 #endif
  68
  69 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  70 /* length of a krb5 verifier (48), plus data added before arguments when
  71  * using integrity (two 4-byte integers): */
  72 #define GSS_VERF_SLACK          100
  73
  74 struct gss_auth {
  75         struct kref kref;
  76         struct rpc_auth rpc_auth;
  77         struct gss_api_mech *mech;
  78         enum rpc_gss_svc service;
  79         struct rpc_clnt *client;
  80         /*
  81          * There are two upcall pipes; dentry[1], named "gssd", is used
  82          * for the new text-based upcall; dentry[0] is named after the
  83          * mechanism (for example, "krb5") and exists for
  84          * backwards-compatibility with older gssd's.
  85          */
  86         struct rpc_pipe *pipe[2];
  87 };
  88
  89 /* pipe_version >= 0 if and only if someone has a pipe open. */
  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, NULL, 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 error %ld\n", __func__, -PTR_ERR(p));
 251         return p;
 252 }
 253
 254 #define UPCALL_BUF_LEN 128
 255
 256 struct gss_upcall_msg {
 257         atomic_t count;
 258         kuid_t  uid;
 259         struct rpc_pipe_msg msg;
 260         struct list_head list;
 261         struct gss_auth *auth;
 262         struct rpc_pipe *pipe;
 263         struct rpc_wait_queue rpc_waitqueue;
 264         wait_queue_head_t waitqueue;
 265         struct gss_cl_ctx *ctx;
 266         char databuf[UPCALL_BUF_LEN];
 267 };
 268
 269 static int get_pipe_version(struct net *net)
 270 {
 271         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 272         int ret;
 273
 274         spin_lock(&pipe_version_lock);
 275         if (sn->pipe_version >= 0) {
 276                 atomic_inc(&sn->pipe_users);
 277                 ret = sn->pipe_version;
 278         } else
 279                 ret = -EAGAIN;
 280         spin_unlock(&pipe_version_lock);
 281         return ret;
 282 }
 283
 284 static void put_pipe_version(struct net *net)
 285 {
 286         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 287
 288         if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
 289                 sn->pipe_version = -1;
 290                 spin_unlock(&pipe_version_lock);
 291         }
 292 }
 293
 294 static void
 295 gss_release_msg(struct gss_upcall_msg *gss_msg)
 296 {
 297         struct net *net = rpc_net_ns(gss_msg->auth->client);
 298         if (!atomic_dec_and_test(&gss_msg->count))
 299                 return;
 300         put_pipe_version(net);
 301         BUG_ON(!list_empty(&gss_msg->list));
 302         if (gss_msg->ctx != NULL)
 303                 gss_put_ctx(gss_msg->ctx);
 304         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 305         kfree(gss_msg);
 306 }
 307
 308 static struct gss_upcall_msg *
 309 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid)
 310 {
 311         struct gss_upcall_msg *pos;
 312         list_for_each_entry(pos, &pipe->in_downcall, list) {
 313                 if (!uid_eq(pos->uid, uid))
 314                         continue;
 315                 atomic_inc(&pos->count);
 316                 dprintk("RPC:       %s found msg %p\n", __func__, pos);
 317                 return pos;
 318         }
 319         dprintk("RPC:       %s found nothing\n", __func__);
 320         return NULL;
 321 }
 322
 323 /* Try to add an upcall to the pipefs queue.
 324  * If an upcall owned by our uid already exists, then we return a reference
 325  * to that upcall instead of adding the new upcall.
 326  */
 327 static inline struct gss_upcall_msg *
 328 gss_add_msg(struct gss_upcall_msg *gss_msg)
 329 {
 330         struct rpc_pipe *pipe = gss_msg->pipe;
 331         struct gss_upcall_msg *old;
 332
 333         spin_lock(&pipe->lock);
 334         old = __gss_find_upcall(pipe, gss_msg->uid);
 335         if (old == NULL) {
 336                 atomic_inc(&gss_msg->count);
 337                 list_add(&gss_msg->list, &pipe->in_downcall);
 338         } else
 339                 gss_msg = old;
 340         spin_unlock(&pipe->lock);
 341         return gss_msg;
 342 }
 343
 344 static void
 345 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 346 {
 347         list_del_init(&gss_msg->list);
 348         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 349         wake_up_all(&gss_msg->waitqueue);
 350         atomic_dec(&gss_msg->count);
 351 }
 352
 353 static void
 354 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 355 {
 356         struct rpc_pipe *pipe = gss_msg->pipe;
 357
 358         if (list_empty(&gss_msg->list))
 359                 return;
 360         spin_lock(&pipe->lock);
 361         if (!list_empty(&gss_msg->list))
 362                 __gss_unhash_msg(gss_msg);
 363         spin_unlock(&pipe->lock);
 364 }
 365
 366 static void
 367 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 368 {
 369         switch (gss_msg->msg.errno) {
 370         case 0:
 371                 if (gss_msg->ctx == NULL)
 372                         break;
 373                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 374                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 375                 break;
 376         case -EKEYEXPIRED:
 377                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 378         }
 379         gss_cred->gc_upcall_timestamp = jiffies;
 380         gss_cred->gc_upcall = NULL;
 381         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 382 }
 383
 384 static void
 385 gss_upcall_callback(struct rpc_task *task)
 386 {
 387         struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 388                         struct gss_cred, gc_base);
 389         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 390         struct rpc_pipe *pipe = gss_msg->pipe;
 391
 392         spin_lock(&pipe->lock);
 393         gss_handle_downcall_result(gss_cred, gss_msg);
 394         spin_unlock(&pipe->lock);
 395         task->tk_status = gss_msg->msg.errno;
 396         gss_release_msg(gss_msg);
 397 }
 398
 399 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 400 {
 401         uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
 402         memcpy(gss_msg->databuf, &uid, sizeof(uid));
 403         gss_msg->msg.data = gss_msg->databuf;
 404         gss_msg->msg.len = sizeof(uid);
 405         BUG_ON(sizeof(uid) > UPCALL_BUF_LEN);
 406 }
 407
 408 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 409                                 struct rpc_clnt *clnt,
 410                                 const char *service_name)
 411 {
 412         struct gss_api_mech *mech = gss_msg->auth->mech;
 413         char *p = gss_msg->databuf;
 414         int len = 0;
 415
 416         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
 417                                    mech->gm_name,
 418                                    from_kuid(&init_user_ns, gss_msg->uid));
 419         p += gss_msg->msg.len;
 420         if (clnt->cl_principal) {
 421                 len = sprintf(p, "target=%s ", clnt->cl_principal);
 422                 p += len;
 423                 gss_msg->msg.len += len;
 424         }
 425         if (service_name != NULL) {
 426                 len = sprintf(p, "service=%s ", service_name);
 427                 p += len;
 428                 gss_msg->msg.len += len;
 429         }
 430         if (mech->gm_upcall_enctypes) {
 431                 len = sprintf(p, "enctypes=%s ", mech->gm_upcall_enctypes);
 432                 p += len;
 433                 gss_msg->msg.len += len;
 434         }
 435         len = sprintf(p, "\n");
 436         gss_msg->msg.len += len;
 437
 438         gss_msg->msg.data = gss_msg->databuf;
 439         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
 440 }
 441
 442 static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
 443                                 struct rpc_clnt *clnt,
 444                                 const char *service_name)
 445 {
 446         struct net *net = rpc_net_ns(clnt);
 447         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 448
 449         if (sn->pipe_version == 0)
 450                 gss_encode_v0_msg(gss_msg);
 451         else /* pipe_version == 1 */
 452                 gss_encode_v1_msg(gss_msg, clnt, service_name);
 453 }
 454
 455 static struct gss_upcall_msg *
 456 gss_alloc_msg(struct gss_auth *gss_auth, struct rpc_clnt *clnt,
 457                 kuid_t uid, const char *service_name)
 458 {
 459         struct gss_upcall_msg *gss_msg;
 460         int vers;
 461
 462         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 463         if (gss_msg == NULL)
 464                 return ERR_PTR(-ENOMEM);
 465         vers = get_pipe_version(rpc_net_ns(clnt));
 466         if (vers < 0) {
 467                 kfree(gss_msg);
 468                 return ERR_PTR(vers);
 469         }
 470         gss_msg->pipe = gss_auth->pipe[vers];
 471         INIT_LIST_HEAD(&gss_msg->list);
 472         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 473         init_waitqueue_head(&gss_msg->waitqueue);
 474         atomic_set(&gss_msg->count, 1);
 475         gss_msg->uid = uid;
 476         gss_msg->auth = gss_auth;
 477         gss_encode_msg(gss_msg, clnt, service_name);
 478         return gss_msg;
 479 }
 480
 481 static struct gss_upcall_msg *
 482 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 483 {
 484         struct gss_cred *gss_cred = container_of(cred,
 485                         struct gss_cred, gc_base);
 486         struct gss_upcall_msg *gss_new, *gss_msg;
 487         kuid_t uid = cred->cr_uid;
 488
 489         gss_new = gss_alloc_msg(gss_auth, clnt, uid, gss_cred->gc_principal);
 490         if (IS_ERR(gss_new))
 491                 return gss_new;
 492         gss_msg = gss_add_msg(gss_new);
 493         if (gss_msg == gss_new) {
 494                 int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 495                 if (res) {
 496                         gss_unhash_msg(gss_new);
 497                         gss_msg = ERR_PTR(res);
 498                 }
 499         } else
 500                 gss_release_msg(gss_new);
 501         return gss_msg;
 502 }
 503
 504 static void warn_gssd(void)
 505 {
 506         static unsigned long ratelimit;
 507         unsigned long now = jiffies;
 508
 509         if (time_after(now, ratelimit)) {
 510                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 511                                 "Please check user daemon is running.\n");
 512                 ratelimit = now + 15*HZ;
 513         }
 514 }
 515
 516 static inline int
 517 gss_refresh_upcall(struct rpc_task *task)
 518 {
 519         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 520         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 521                         struct gss_auth, rpc_auth);
 522         struct gss_cred *gss_cred = container_of(cred,
 523                         struct gss_cred, gc_base);
 524         struct gss_upcall_msg *gss_msg;
 525         struct rpc_pipe *pipe;
 526         int err = 0;
 527
 528         dprintk("RPC: %5u %s for uid %u\n",
 529                 task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
 530         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 531         if (PTR_ERR(gss_msg) == -EAGAIN) {
 532                 /* XXX: warning on the first, under the assumption we
 533                  * shouldn't normally hit this case on a refresh. */
 534                 warn_gssd();
 535                 task->tk_timeout = 15*HZ;
 536                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 537                 return -EAGAIN;
 538         }
 539         if (IS_ERR(gss_msg)) {
 540                 err = PTR_ERR(gss_msg);
 541                 goto out;
 542         }
 543         pipe = gss_msg->pipe;
 544         spin_lock(&pipe->lock);
 545         if (gss_cred->gc_upcall != NULL)
 546                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 547         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 548                 task->tk_timeout = 0;
 549                 gss_cred->gc_upcall = gss_msg;
 550                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 551                 atomic_inc(&gss_msg->count);
 552                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 553         } else {
 554                 gss_handle_downcall_result(gss_cred, gss_msg);
 555                 err = gss_msg->msg.errno;
 556         }
 557         spin_unlock(&pipe->lock);
 558         gss_release_msg(gss_msg);
 559 out:
 560         dprintk("RPC: %5u %s for uid %u result %d\n",
 561                 task->tk_pid, __func__,
 562                 from_kuid(&init_user_ns, cred->cr_uid), err);
 563         return err;
 564 }
 565
 566 static inline int
 567 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 568 {
 569         struct net *net = rpc_net_ns(gss_auth->client);
 570         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 571         struct rpc_pipe *pipe;
 572         struct rpc_cred *cred = &gss_cred->gc_base;
 573         struct gss_upcall_msg *gss_msg;
 574         unsigned long timeout;
 575         DEFINE_WAIT(wait);
 576         int err;
 577
 578         dprintk("RPC:       %s for uid %u\n",
 579                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 580 retry:
 581         err = 0;
 582         /* Default timeout is 15s unless we know that gssd is not running */
 583         timeout = 15 * HZ;
 584         if (!sn->gssd_running)
 585                 timeout = HZ >> 2;
 586         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 587         if (PTR_ERR(gss_msg) == -EAGAIN) {
 588                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 589                                 sn->pipe_version >= 0, timeout);
 590                 if (sn->pipe_version < 0) {
 591                         if (err == 0)
 592                                 sn->gssd_running = 0;
 593                         warn_gssd();
 594                         err = -EACCES;
 595                 }
 596                 if (err < 0)
 597                         goto out;
 598                 goto retry;
 599         }
 600         if (IS_ERR(gss_msg)) {
 601                 err = PTR_ERR(gss_msg);
 602                 goto out;
 603         }
 604         pipe = gss_msg->pipe;
 605         for (;;) {
 606                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 607                 spin_lock(&pipe->lock);
 608                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 609                         break;
 610                 }
 611                 spin_unlock(&pipe->lock);
 612                 if (fatal_signal_pending(current)) {
 613                         err = -ERESTARTSYS;
 614                         goto out_intr;
 615                 }
 616                 schedule();
 617         }
 618         if (gss_msg->ctx)
 619                 gss_cred_set_ctx(cred, gss_msg->ctx);
 620         else
 621                 err = gss_msg->msg.errno;
 622         spin_unlock(&pipe->lock);
 623 out_intr:
 624         finish_wait(&gss_msg->waitqueue, &wait);
 625         gss_release_msg(gss_msg);
 626 out:
 627         dprintk("RPC:       %s for uid %u result %d\n",
 628                 __func__, from_kuid(&init_user_ns, cred->cr_uid), err);
 629         return err;
 630 }
 631
 632 #define MSG_BUF_MAXSIZE 1024
 633
 634 static ssize_t
 635 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 636 {
 637         const void *p, *end;
 638         void *buf;
 639         struct gss_upcall_msg *gss_msg;
 640         struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 641         struct gss_cl_ctx *ctx;
 642         uid_t id;
 643         kuid_t uid;
 644         ssize_t err = -EFBIG;
 645
 646         if (mlen > MSG_BUF_MAXSIZE)
 647                 goto out;
 648         err = -ENOMEM;
 649         buf = kmalloc(mlen, GFP_NOFS);
 650         if (!buf)
 651                 goto out;
 652
 653         err = -EFAULT;
 654         if (copy_from_user(buf, src, mlen))
 655                 goto err;
 656
 657         end = (const void *)((char *)buf + mlen);
 658         p = simple_get_bytes(buf, end, &id, sizeof(id));
 659         if (IS_ERR(p)) {
 660                 err = PTR_ERR(p);
 661                 goto err;
 662         }
 663
 664         uid = make_kuid(&init_user_ns, id);
 665         if (!uid_valid(uid)) {
 666                 err = -EINVAL;
 667                 goto err;
 668         }
 669
 670         err = -ENOMEM;
 671         ctx = gss_alloc_context();
 672         if (ctx == NULL)
 673                 goto err;
 674
 675         err = -ENOENT;
 676         /* Find a matching upcall */
 677         spin_lock(&pipe->lock);
 678         gss_msg = __gss_find_upcall(pipe, uid);
 679         if (gss_msg == NULL) {
 680                 spin_unlock(&pipe->lock);
 681                 goto err_put_ctx;
 682         }
 683         list_del_init(&gss_msg->list);
 684         spin_unlock(&pipe->lock);
 685
 686         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 687         if (IS_ERR(p)) {
 688                 err = PTR_ERR(p);
 689                 switch (err) {
 690                 case -EACCES:
 691                 case -EKEYEXPIRED:
 692                         gss_msg->msg.errno = err;
 693                         err = mlen;
 694                         break;
 695                 case -EFAULT:
 696                 case -ENOMEM:
 697                 case -EINVAL:
 698                 case -ENOSYS:
 699                         gss_msg->msg.errno = -EAGAIN;
 700                         break;
 701                 default:
 702                         printk(KERN_CRIT "%s: bad return from "
 703                                 "gss_fill_context: %zd\n", __func__, err);
 704                         BUG();
 705                 }
 706                 goto err_release_msg;
 707         }
 708         gss_msg->ctx = gss_get_ctx(ctx);
 709         err = mlen;
 710
 711 err_release_msg:
 712         spin_lock(&pipe->lock);
 713         __gss_unhash_msg(gss_msg);
 714         spin_unlock(&pipe->lock);
 715         gss_release_msg(gss_msg);
 716 err_put_ctx:
 717         gss_put_ctx(ctx);
 718 err:
 719         kfree(buf);
 720 out:
 721         dprintk("RPC:       %s returning %Zd\n", __func__, err);
 722         return err;
 723 }
 724
 725 static int gss_pipe_open(struct inode *inode, int new_version)
 726 {
 727         struct net *net = inode->i_sb->s_fs_info;
 728         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 729         int ret = 0;
 730
 731         spin_lock(&pipe_version_lock);
 732         if (sn->pipe_version < 0) {
 733                 /* First open of any gss pipe determines the version: */
 734                 sn->pipe_version = new_version;
 735                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 736                 wake_up(&pipe_version_waitqueue);
 737         } else if (sn->pipe_version != new_version) {
 738                 /* Trying to open a pipe of a different version */
 739                 ret = -EBUSY;
 740                 goto out;
 741         }
 742         atomic_inc(&sn->pipe_users);
 743 out:
 744         spin_unlock(&pipe_version_lock);
 745         return ret;
 746
 747 }
 748
 749 static int gss_pipe_open_v0(struct inode *inode)
 750 {
 751         return gss_pipe_open(inode, 0);
 752 }
 753
 754 static int gss_pipe_open_v1(struct inode *inode)
 755 {
 756         return gss_pipe_open(inode, 1);
 757 }
 758
 759 static void
 760 gss_pipe_release(struct inode *inode)
 761 {
 762         struct net *net = inode->i_sb->s_fs_info;
 763         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 764         struct gss_upcall_msg *gss_msg;
 765
 766 restart:
 767         spin_lock(&pipe->lock);
 768         list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 769
 770                 if (!list_empty(&gss_msg->msg.list))
 771                         continue;
 772                 gss_msg->msg.errno = -EPIPE;
 773                 atomic_inc(&gss_msg->count);
 774                 __gss_unhash_msg(gss_msg);
 775                 spin_unlock(&pipe->lock);
 776                 gss_release_msg(gss_msg);
 777                 goto restart;
 778         }
 779         spin_unlock(&pipe->lock);
 780
 781         put_pipe_version(net);
 782 }
 783
 784 static void
 785 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 786 {
 787         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 788
 789         if (msg->errno < 0) {
 790                 dprintk("RPC:       %s releasing msg %p\n",
 791                         __func__, gss_msg);
 792                 atomic_inc(&gss_msg->count);
 793                 gss_unhash_msg(gss_msg);
 794                 if (msg->errno == -ETIMEDOUT)
 795                         warn_gssd();
 796                 gss_release_msg(gss_msg);
 797         }
 798 }
 799
 800 static void gss_pipes_dentries_destroy(struct rpc_auth *auth)
 801 {
 802         struct gss_auth *gss_auth;
 803
 804         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 805         if (gss_auth->pipe[0]->dentry)
 806                 rpc_unlink(gss_auth->pipe[0]->dentry);
 807         if (gss_auth->pipe[1]->dentry)
 808                 rpc_unlink(gss_auth->pipe[1]->dentry);
 809 }
 810
 811 static int gss_pipes_dentries_create(struct rpc_auth *auth)
 812 {
 813         int err;
 814         struct gss_auth *gss_auth;
 815         struct rpc_clnt *clnt;
 816
 817         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 818         clnt = gss_auth->client;
 819
 820         gss_auth->pipe[1]->dentry = rpc_mkpipe_dentry(clnt->cl_dentry,
 821                                                       "gssd",
 822                                                       clnt, gss_auth->pipe[1]);
 823         if (IS_ERR(gss_auth->pipe[1]->dentry))
 824                 return PTR_ERR(gss_auth->pipe[1]->dentry);
 825         gss_auth->pipe[0]->dentry = rpc_mkpipe_dentry(clnt->cl_dentry,
 826                                                       gss_auth->mech->gm_name,
 827                                                       clnt, gss_auth->pipe[0]);
 828         if (IS_ERR(gss_auth->pipe[0]->dentry)) {
 829                 err = PTR_ERR(gss_auth->pipe[0]->dentry);
 830                 goto err_unlink_pipe_1;
 831         }
 832         return 0;
 833
 834 err_unlink_pipe_1:
 835         rpc_unlink(gss_auth->pipe[1]->dentry);
 836         return err;
 837 }
 838
 839 static void gss_pipes_dentries_destroy_net(struct rpc_clnt *clnt,
 840                                            struct rpc_auth *auth)
 841 {
 842         struct net *net = rpc_net_ns(clnt);
 843         struct super_block *sb;
 844
 845         sb = rpc_get_sb_net(net);
 846         if (sb) {
 847                 if (clnt->cl_dentry)
 848                         gss_pipes_dentries_destroy(auth);
 849                 rpc_put_sb_net(net);
 850         }
 851 }
 852
 853 static int gss_pipes_dentries_create_net(struct rpc_clnt *clnt,
 854                                          struct rpc_auth *auth)
 855 {
 856         struct net *net = rpc_net_ns(clnt);
 857         struct super_block *sb;
 858         int err = 0;
 859
 860         sb = rpc_get_sb_net(net);
 861         if (sb) {
 862                 if (clnt->cl_dentry)
 863                         err = gss_pipes_dentries_create(auth);
 864                 rpc_put_sb_net(net);
 865         }
 866         return err;
 867 }
 868
 869 /*
 870  * NOTE: we have the opportunity to use different
 871  * parameters based on the input flavor (which must be a pseudoflavor)
 872  */
 873 static struct rpc_auth *
 874 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 875 {
 876         struct gss_auth *gss_auth;
 877         struct rpc_auth * auth;
 878         int err = -ENOMEM; /* XXX? */
 879
 880         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 881
 882         if (!try_module_get(THIS_MODULE))
 883                 return ERR_PTR(err);
 884         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 885                 goto out_dec;
 886         gss_auth->client = clnt;
 887         err = -EINVAL;
 888         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 889         if (!gss_auth->mech) {
 890                 dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
 891                 goto err_free;
 892         }
 893         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 894         if (gss_auth->service == 0)
 895                 goto err_put_mech;
 896         auth = &gss_auth->rpc_auth;
 897         auth->au_cslack = GSS_CRED_SLACK >> 2;
 898         auth->au_rslack = GSS_VERF_SLACK >> 2;
 899         auth->au_ops = &authgss_ops;
 900         auth->au_flavor = flavor;
 901         atomic_set(&auth->au_count, 1);
 902         kref_init(&gss_auth->kref);
 903
 904         /*
 905          * Note: if we created the old pipe first, then someone who
 906          * examined the directory at the right moment might conclude
 907          * that we supported only the old pipe.  So we instead create
 908          * the new pipe first.
 909          */
 910         gss_auth->pipe[1] = rpc_mkpipe_data(&gss_upcall_ops_v1,
 911                                             RPC_PIPE_WAIT_FOR_OPEN);
 912         if (IS_ERR(gss_auth->pipe[1])) {
 913                 err = PTR_ERR(gss_auth->pipe[1]);
 914                 goto err_put_mech;
 915         }
 916
 917         gss_auth->pipe[0] = rpc_mkpipe_data(&gss_upcall_ops_v0,
 918                                             RPC_PIPE_WAIT_FOR_OPEN);
 919         if (IS_ERR(gss_auth->pipe[0])) {
 920                 err = PTR_ERR(gss_auth->pipe[0]);
 921                 goto err_destroy_pipe_1;
 922         }
 923         err = gss_pipes_dentries_create_net(clnt, auth);
 924         if (err)
 925                 goto err_destroy_pipe_0;
 926         err = rpcauth_init_credcache(auth);
 927         if (err)
 928                 goto err_unlink_pipes;
 929
 930         return auth;
 931 err_unlink_pipes:
 932         gss_pipes_dentries_destroy_net(clnt, auth);
 933 err_destroy_pipe_0:
 934         rpc_destroy_pipe_data(gss_auth->pipe[0]);
 935 err_destroy_pipe_1:
 936         rpc_destroy_pipe_data(gss_auth->pipe[1]);
 937 err_put_mech:
 938         gss_mech_put(gss_auth->mech);
 939 err_free:
 940         kfree(gss_auth);
 941 out_dec:
 942         module_put(THIS_MODULE);
 943         return ERR_PTR(err);
 944 }
 945
 946 static void
 947 gss_free(struct gss_auth *gss_auth)
 948 {
 949         gss_pipes_dentries_destroy_net(gss_auth->client, &gss_auth->rpc_auth);
 950         rpc_destroy_pipe_data(gss_auth->pipe[0]);
 951         rpc_destroy_pipe_data(gss_auth->pipe[1]);
 952         gss_mech_put(gss_auth->mech);
 953
 954         kfree(gss_auth);
 955         module_put(THIS_MODULE);
 956 }
 957
 958 static void
 959 gss_free_callback(struct kref *kref)
 960 {
 961         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 962
 963         gss_free(gss_auth);
 964 }
 965
 966 static void
 967 gss_destroy(struct rpc_auth *auth)
 968 {
 969         struct gss_auth *gss_auth;
 970
 971         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 972                         auth, auth->au_flavor);
 973
 974         rpcauth_destroy_credcache(auth);
 975
 976         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 977         kref_put(&gss_auth->kref, gss_free_callback);
 978 }
 979
 980 /*
 981  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 982  * to the server with the GSS control procedure field set to
 983  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 984  * all RPCSEC_GSS state associated with that context.
 985  */
 986 static int
 987 gss_destroying_context(struct rpc_cred *cred)
 988 {
 989         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 990         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 991         struct rpc_task *task;
 992
 993         if (gss_cred->gc_ctx == NULL ||
 994             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 995                 return 0;
 996
 997         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 998         cred->cr_ops = &gss_nullops;
 999
1000         /* Take a reference to ensure the cred will be destroyed either
1001          * by the RPC call or by the put_rpccred() below */
1002         get_rpccred(cred);
1003
1004         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1005         if (!IS_ERR(task))
1006                 rpc_put_task(task);
1007
1008         put_rpccred(cred);
1009         return 1;
1010 }
1011
1012 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1013  * to create a new cred or context, so they check that things have been
1014  * allocated before freeing them. */
1015 static void
1016 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1017 {
1018         dprintk("RPC:       %s\n", __func__);
1019
1020         gss_delete_sec_context(&ctx->gc_gss_ctx);
1021         kfree(ctx->gc_wire_ctx.data);
1022         kfree(ctx);
1023 }
1024
1025 static void
1026 gss_free_ctx_callback(struct rcu_head *head)
1027 {
1028         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1029         gss_do_free_ctx(ctx);
1030 }
1031
1032 static void
1033 gss_free_ctx(struct gss_cl_ctx *ctx)
1034 {
1035         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1036 }
1037
1038 static void
1039 gss_free_cred(struct gss_cred *gss_cred)
1040 {
1041         dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1042         kfree(gss_cred);
1043 }
1044
1045 static void
1046 gss_free_cred_callback(struct rcu_head *head)
1047 {
1048         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1049         gss_free_cred(gss_cred);
1050 }
1051
1052 static void
1053 gss_destroy_nullcred(struct rpc_cred *cred)
1054 {
1055         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1056         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1057         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
1058
1059         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1060         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1061         if (ctx)
1062                 gss_put_ctx(ctx);
1063         kref_put(&gss_auth->kref, gss_free_callback);
1064 }
1065
1066 static void
1067 gss_destroy_cred(struct rpc_cred *cred)
1068 {
1069
1070         if (gss_destroying_context(cred))
1071                 return;
1072         gss_destroy_nullcred(cred);
1073 }
1074
1075 /*
1076  * Lookup RPCSEC_GSS cred for the current process
1077  */
1078 static struct rpc_cred *
1079 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1080 {
1081         return rpcauth_lookup_credcache(auth, acred, flags);
1082 }
1083
1084 static struct rpc_cred *
1085 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1086 {
1087         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1088         struct gss_cred *cred = NULL;
1089         int err = -ENOMEM;
1090
1091         dprintk("RPC:       %s for uid %d, flavor %d\n",
1092                 __func__, from_kuid(&init_user_ns, acred->uid),
1093                 auth->au_flavor);
1094
1095         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1096                 goto out_err;
1097
1098         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1099         /*
1100          * Note: in order to force a call to call_refresh(), we deliberately
1101          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1102          */
1103         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1104         cred->gc_service = gss_auth->service;
1105         cred->gc_principal = NULL;
1106         if (acred->machine_cred)
1107                 cred->gc_principal = acred->principal;
1108         kref_get(&gss_auth->kref);
1109         return &cred->gc_base;
1110
1111 out_err:
1112         dprintk("RPC:       %s failed with error %d\n", __func__, err);
1113         return ERR_PTR(err);
1114 }
1115
1116 static int
1117 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1118 {
1119         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1120         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1121         int err;
1122
1123         do {
1124                 err = gss_create_upcall(gss_auth, gss_cred);
1125         } while (err == -EAGAIN);
1126         return err;
1127 }
1128
1129 static int
1130 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1131 {
1132         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1133
1134         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1135                 goto out;
1136         /* Don't match with creds that have expired. */
1137         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1138                 return 0;
1139         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1140                 return 0;
1141 out:
1142         if (acred->principal != NULL) {
1143                 if (gss_cred->gc_principal == NULL)
1144                         return 0;
1145                 return strcmp(acred->principal, gss_cred->gc_principal) == 0;
1146         }
1147         if (gss_cred->gc_principal != NULL)
1148                 return 0;
1149         return uid_eq(rc->cr_uid, acred->uid);
1150 }
1151
1152 /*
1153 * Marshal credentials.
1154 * Maybe we should keep a cached credential for performance reasons.
1155 */
1156 static __be32 *
1157 gss_marshal(struct rpc_task *task, __be32 *p)
1158 {
1159         struct rpc_rqst *req = task->tk_rqstp;
1160         struct rpc_cred *cred = req->rq_cred;
1161         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1162                                                  gc_base);
1163         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1164         __be32          *cred_len;
1165         u32             maj_stat = 0;
1166         struct xdr_netobj mic;
1167         struct kvec     iov;
1168         struct xdr_buf  verf_buf;
1169
1170         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1171
1172         *p++ = htonl(RPC_AUTH_GSS);
1173         cred_len = p++;
1174
1175         spin_lock(&ctx->gc_seq_lock);
1176         req->rq_seqno = ctx->gc_seq++;
1177         spin_unlock(&ctx->gc_seq_lock);
1178
1179         *p++ = htonl((u32) RPC_GSS_VERSION);
1180         *p++ = htonl((u32) ctx->gc_proc);
1181         *p++ = htonl((u32) req->rq_seqno);
1182         *p++ = htonl((u32) gss_cred->gc_service);
1183         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1184         *cred_len = htonl((p - (cred_len + 1)) << 2);
1185
1186         /* We compute the checksum for the verifier over the xdr-encoded bytes
1187          * starting with the xid and ending at the end of the credential: */
1188         iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1189                                         req->rq_snd_buf.head[0].iov_base);
1190         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1191         xdr_buf_from_iov(&iov, &verf_buf);
1192
1193         /* set verifier flavor*/
1194         *p++ = htonl(RPC_AUTH_GSS);
1195
1196         mic.data = (u8 *)(p + 1);
1197         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1198         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1199                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1200         } else if (maj_stat != 0) {
1201                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1202                 goto out_put_ctx;
1203         }
1204         p = xdr_encode_opaque(p, NULL, mic.len);
1205         gss_put_ctx(ctx);
1206         return p;
1207 out_put_ctx:
1208         gss_put_ctx(ctx);
1209         return NULL;
1210 }
1211
1212 static int gss_renew_cred(struct rpc_task *task)
1213 {
1214         struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1215         struct gss_cred *gss_cred = container_of(oldcred,
1216                                                  struct gss_cred,
1217                                                  gc_base);
1218         struct rpc_auth *auth = oldcred->cr_auth;
1219         struct auth_cred acred = {
1220                 .uid = oldcred->cr_uid,
1221                 .principal = gss_cred->gc_principal,
1222                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1223         };
1224         struct rpc_cred *new;
1225
1226         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1227         if (IS_ERR(new))
1228                 return PTR_ERR(new);
1229         task->tk_rqstp->rq_cred = new;
1230         put_rpccred(oldcred);
1231         return 0;
1232 }
1233
1234 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1235 {
1236         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1237                 unsigned long now = jiffies;
1238                 unsigned long begin, expire;
1239                 struct gss_cred *gss_cred;
1240
1241                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1242                 begin = gss_cred->gc_upcall_timestamp;
1243                 expire = begin + gss_expired_cred_retry_delay * HZ;
1244
1245                 if (time_in_range_open(now, begin, expire))
1246                         return 1;
1247         }
1248         return 0;
1249 }
1250
1251 /*
1252 * Refresh credentials. XXX - finish
1253 */
1254 static int
1255 gss_refresh(struct rpc_task *task)
1256 {
1257         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1258         int ret = 0;
1259
1260         if (gss_cred_is_negative_entry(cred))
1261                 return -EKEYEXPIRED;
1262
1263         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1264                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1265                 ret = gss_renew_cred(task);
1266                 if (ret < 0)
1267                         goto out;
1268                 cred = task->tk_rqstp->rq_cred;
1269         }
1270
1271         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1272                 ret = gss_refresh_upcall(task);
1273 out:
1274         return ret;
1275 }
1276
1277 /* Dummy refresh routine: used only when destroying the context */
1278 static int
1279 gss_refresh_null(struct rpc_task *task)
1280 {
1281         return -EACCES;
1282 }
1283
1284 static __be32 *
1285 gss_validate(struct rpc_task *task, __be32 *p)
1286 {
1287         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1288         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1289         __be32          seq;
1290         struct kvec     iov;
1291         struct xdr_buf  verf_buf;
1292         struct xdr_netobj mic;
1293         u32             flav,len;
1294         u32             maj_stat;
1295
1296         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1297
1298         flav = ntohl(*p++);
1299         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1300                 goto out_bad;
1301         if (flav != RPC_AUTH_GSS)
1302                 goto out_bad;
1303         seq = htonl(task->tk_rqstp->rq_seqno);
1304         iov.iov_base = &seq;
1305         iov.iov_len = sizeof(seq);
1306         xdr_buf_from_iov(&iov, &verf_buf);
1307         mic.data = (u8 *)p;
1308         mic.len = len;
1309
1310         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1311         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1312                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1313         if (maj_stat) {
1314                 dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1315                         task->tk_pid, __func__, maj_stat);
1316                 goto out_bad;
1317         }
1318         /* We leave it to unwrap to calculate au_rslack. For now we just
1319          * calculate the length of the verifier: */
1320         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1321         gss_put_ctx(ctx);
1322         dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1323                         task->tk_pid, __func__);
1324         return p + XDR_QUADLEN(len);
1325 out_bad:
1326         gss_put_ctx(ctx);
1327         dprintk("RPC: %5u %s failed.\n", task->tk_pid, __func__);
1328         return NULL;
1329 }
1330
1331 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1332                                 __be32 *p, void *obj)
1333 {
1334         struct xdr_stream xdr;
1335
1336         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1337         encode(rqstp, &xdr, obj);
1338 }
1339
1340 static inline int
1341 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1342                    kxdreproc_t encode, struct rpc_rqst *rqstp,
1343                    __be32 *p, void *obj)
1344 {
1345         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1346         struct xdr_buf  integ_buf;
1347         __be32          *integ_len = NULL;
1348         struct xdr_netobj mic;
1349         u32             offset;
1350         __be32          *q;
1351         struct kvec     *iov;
1352         u32             maj_stat = 0;
1353         int             status = -EIO;
1354
1355         integ_len = p++;
1356         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1357         *p++ = htonl(rqstp->rq_seqno);
1358
1359         gss_wrap_req_encode(encode, rqstp, p, obj);
1360
1361         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1362                                 offset, snd_buf->len - offset))
1363                 return status;
1364         *integ_len = htonl(integ_buf.len);
1365
1366         /* guess whether we're in the head or the tail: */
1367         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1368                 iov = snd_buf->tail;
1369         else
1370                 iov = snd_buf->head;
1371         p = iov->iov_base + iov->iov_len;
1372         mic.data = (u8 *)(p + 1);
1373
1374         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1375         status = -EIO; /* XXX? */
1376         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1377                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1378         else if (maj_stat)
1379                 return status;
1380         q = xdr_encode_opaque(p, NULL, mic.len);
1381
1382         offset = (u8 *)q - (u8 *)p;
1383         iov->iov_len += offset;
1384         snd_buf->len += offset;
1385         return 0;
1386 }
1387
1388 static void
1389 priv_release_snd_buf(struct rpc_rqst *rqstp)
1390 {
1391         int i;
1392
1393         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1394                 __free_page(rqstp->rq_enc_pages[i]);
1395         kfree(rqstp->rq_enc_pages);
1396 }
1397
1398 static int
1399 alloc_enc_pages(struct rpc_rqst *rqstp)
1400 {
1401         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1402         int first, last, i;
1403
1404         if (snd_buf->page_len == 0) {
1405                 rqstp->rq_enc_pages_num = 0;
1406                 return 0;
1407         }
1408
1409         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1410         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1411         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1412         rqstp->rq_enc_pages
1413                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1414                                 GFP_NOFS);
1415         if (!rqstp->rq_enc_pages)
1416                 goto out;
1417         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1418                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1419                 if (rqstp->rq_enc_pages[i] == NULL)
1420                         goto out_free;
1421         }
1422         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1423         return 0;
1424 out_free:
1425         rqstp->rq_enc_pages_num = i;
1426         priv_release_snd_buf(rqstp);
1427 out:
1428         return -EAGAIN;
1429 }
1430
1431 static inline int
1432 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1433                   kxdreproc_t encode, struct rpc_rqst *rqstp,
1434                   __be32 *p, void *obj)
1435 {
1436         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1437         u32             offset;
1438         u32             maj_stat;
1439         int             status;
1440         __be32          *opaque_len;
1441         struct page     **inpages;
1442         int             first;
1443         int             pad;
1444         struct kvec     *iov;
1445         char            *tmp;
1446
1447         opaque_len = p++;
1448         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1449         *p++ = htonl(rqstp->rq_seqno);
1450
1451         gss_wrap_req_encode(encode, rqstp, p, obj);
1452
1453         status = alloc_enc_pages(rqstp);
1454         if (status)
1455                 return status;
1456         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1457         inpages = snd_buf->pages + first;
1458         snd_buf->pages = rqstp->rq_enc_pages;
1459         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1460         /*
1461          * Give the tail its own page, in case we need extra space in the
1462          * head when wrapping:
1463          *
1464          * call_allocate() allocates twice the slack space required
1465          * by the authentication flavor to rq_callsize.
1466          * For GSS, slack is GSS_CRED_SLACK.
1467          */
1468         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1469                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1470                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1471                 snd_buf->tail[0].iov_base = tmp;
1472         }
1473         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1474         /* slack space should prevent this ever happening: */
1475         BUG_ON(snd_buf->len > snd_buf->buflen);
1476         status = -EIO;
1477         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1478          * done anyway, so it's safe to put the request on the wire: */
1479         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1480                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1481         else if (maj_stat)
1482                 return status;
1483
1484         *opaque_len = htonl(snd_buf->len - offset);
1485         /* guess whether we're in the head or the tail: */
1486         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1487                 iov = snd_buf->tail;
1488         else
1489                 iov = snd_buf->head;
1490         p = iov->iov_base + iov->iov_len;
1491         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1492         memset(p, 0, pad);
1493         iov->iov_len += pad;
1494         snd_buf->len += pad;
1495
1496         return 0;
1497 }
1498
1499 static int
1500 gss_wrap_req(struct rpc_task *task,
1501              kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1502 {
1503         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1504         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1505                         gc_base);
1506         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1507         int             status = -EIO;
1508
1509         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1510         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1511                 /* The spec seems a little ambiguous here, but I think that not
1512                  * wrapping context destruction requests makes the most sense.
1513                  */
1514                 gss_wrap_req_encode(encode, rqstp, p, obj);
1515                 status = 0;
1516                 goto out;
1517         }
1518         switch (gss_cred->gc_service) {
1519         case RPC_GSS_SVC_NONE:
1520                 gss_wrap_req_encode(encode, rqstp, p, obj);
1521                 status = 0;
1522                 break;
1523         case RPC_GSS_SVC_INTEGRITY:
1524                 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1525                 break;
1526         case RPC_GSS_SVC_PRIVACY:
1527                 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1528                 break;
1529         }
1530 out:
1531         gss_put_ctx(ctx);
1532         dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1533         return status;
1534 }
1535
1536 static inline int
1537 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1538                 struct rpc_rqst *rqstp, __be32 **p)
1539 {
1540         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1541         struct xdr_buf integ_buf;
1542         struct xdr_netobj mic;
1543         u32 data_offset, mic_offset;
1544         u32 integ_len;
1545         u32 maj_stat;
1546         int status = -EIO;
1547
1548         integ_len = ntohl(*(*p)++);
1549         if (integ_len & 3)
1550                 return status;
1551         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1552         mic_offset = integ_len + data_offset;
1553         if (mic_offset > rcv_buf->len)
1554                 return status;
1555         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1556                 return status;
1557
1558         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1559                                 mic_offset - data_offset))
1560                 return status;
1561
1562         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1563                 return status;
1564
1565         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1566         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1567                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1568         if (maj_stat != GSS_S_COMPLETE)
1569                 return status;
1570         return 0;
1571 }
1572
1573 static inline int
1574 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1575                 struct rpc_rqst *rqstp, __be32 **p)
1576 {
1577         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1578         u32 offset;
1579         u32 opaque_len;
1580         u32 maj_stat;
1581         int status = -EIO;
1582
1583         opaque_len = ntohl(*(*p)++);
1584         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1585         if (offset + opaque_len > rcv_buf->len)
1586                 return status;
1587         /* remove padding: */
1588         rcv_buf->len = offset + opaque_len;
1589
1590         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1591         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1592                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1593         if (maj_stat != GSS_S_COMPLETE)
1594                 return status;
1595         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1596                 return status;
1597
1598         return 0;
1599 }
1600
1601 static int
1602 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1603                       __be32 *p, void *obj)
1604 {
1605         struct xdr_stream xdr;
1606
1607         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1608         return decode(rqstp, &xdr, obj);
1609 }
1610
1611 static int
1612 gss_unwrap_resp(struct rpc_task *task,
1613                 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1614 {
1615         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1616         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1617                         gc_base);
1618         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1619         __be32          *savedp = p;
1620         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1621         int             savedlen = head->iov_len;
1622         int             status = -EIO;
1623
1624         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1625                 goto out_decode;
1626         switch (gss_cred->gc_service) {
1627         case RPC_GSS_SVC_NONE:
1628                 break;
1629         case RPC_GSS_SVC_INTEGRITY:
1630                 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1631                 if (status)
1632                         goto out;
1633                 break;
1634         case RPC_GSS_SVC_PRIVACY:
1635                 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1636                 if (status)
1637                         goto out;
1638                 break;
1639         }
1640         /* take into account extra slack for integrity and privacy cases: */
1641         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1642                                                 + (savedlen - head->iov_len);
1643 out_decode:
1644         status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1645 out:
1646         gss_put_ctx(ctx);
1647         dprintk("RPC: %5u %s returning %d\n",
1648                 task->tk_pid, __func__, status);
1649         return status;
1650 }
1651
1652 static const struct rpc_authops authgss_ops = {
1653         .owner          = THIS_MODULE,
1654         .au_flavor      = RPC_AUTH_GSS,
1655         .au_name        = "RPCSEC_GSS",
1656         .create         = gss_create,
1657         .destroy        = gss_destroy,
1658         .lookup_cred    = gss_lookup_cred,
1659         .crcreate       = gss_create_cred,
1660         .pipes_create   = gss_pipes_dentries_create,
1661         .pipes_destroy  = gss_pipes_dentries_destroy,
1662         .list_pseudoflavors = gss_mech_list_pseudoflavors,
1663         .info2flavor    = gss_mech_info2flavor,
1664         .flavor2info    = gss_mech_flavor2info,
1665 };
1666
1667 static const struct rpc_credops gss_credops = {
1668         .cr_name        = "AUTH_GSS",
1669         .crdestroy      = gss_destroy_cred,
1670         .cr_init        = gss_cred_init,
1671         .crbind         = rpcauth_generic_bind_cred,
1672         .crmatch        = gss_match,
1673         .crmarshal      = gss_marshal,
1674         .crrefresh      = gss_refresh,
1675         .crvalidate     = gss_validate,
1676         .crwrap_req     = gss_wrap_req,
1677         .crunwrap_resp  = gss_unwrap_resp,
1678 };
1679
1680 static const struct rpc_credops gss_nullops = {
1681         .cr_name        = "AUTH_GSS",
1682         .crdestroy      = gss_destroy_nullcred,
1683         .crbind         = rpcauth_generic_bind_cred,
1684         .crmatch        = gss_match,
1685         .crmarshal      = gss_marshal,
1686         .crrefresh      = gss_refresh_null,
1687         .crvalidate     = gss_validate,
1688         .crwrap_req     = gss_wrap_req,
1689         .crunwrap_resp  = gss_unwrap_resp,
1690 };
1691
1692 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1693         .upcall         = rpc_pipe_generic_upcall,
1694         .downcall       = gss_pipe_downcall,
1695         .destroy_msg    = gss_pipe_destroy_msg,
1696         .open_pipe      = gss_pipe_open_v0,
1697         .release_pipe   = gss_pipe_release,
1698 };
1699
1700 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1701         .upcall         = rpc_pipe_generic_upcall,
1702         .downcall       = gss_pipe_downcall,
1703         .destroy_msg    = gss_pipe_destroy_msg,
1704         .open_pipe      = gss_pipe_open_v1,
1705         .release_pipe   = gss_pipe_release,
1706 };
1707
1708 static __net_init int rpcsec_gss_init_net(struct net *net)
1709 {
1710         return gss_svc_init_net(net);
1711 }
1712
1713 static __net_exit void rpcsec_gss_exit_net(struct net *net)
1714 {
1715         gss_svc_shutdown_net(net);
1716 }
1717
1718 static struct pernet_operations rpcsec_gss_net_ops = {
1719         .init = rpcsec_gss_init_net,
1720         .exit = rpcsec_gss_exit_net,
1721 };
1722
1723 /*
1724  * Initialize RPCSEC_GSS module
1725  */
1726 static int __init init_rpcsec_gss(void)
1727 {
1728         int err = 0;
1729
1730         err = rpcauth_register(&authgss_ops);
1731         if (err)
1732                 goto out;
1733         err = gss_svc_init();
1734         if (err)
1735                 goto out_unregister;
1736         err = register_pernet_subsys(&rpcsec_gss_net_ops);
1737         if (err)
1738                 goto out_svc_exit;
1739         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1740         return 0;
1741 out_svc_exit:
1742         gss_svc_shutdown();
1743 out_unregister:
1744         rpcauth_unregister(&authgss_ops);
1745 out:
1746         return err;
1747 }
1748
1749 static void __exit exit_rpcsec_gss(void)
1750 {
1751         unregister_pernet_subsys(&rpcsec_gss_net_ops);
1752         gss_svc_shutdown();
1753         rpcauth_unregister(&authgss_ops);
1754         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1755 }
1756
1757 MODULE_ALIAS("rpc-auth-6");
1758 MODULE_LICENSE("GPL");
1759 module_param_named(expired_cred_retry_delay,
1760                    gss_expired_cred_retry_delay,
1761                    uint, 0644);
1762 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
1763                 "the RPC engine retries an expired credential");
1764
1765 module_init(init_rpcsec_gss)
1766 module_exit(exit_rpcsec_gss)