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