net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54
  55 static const struct rpc_authops authgss_ops;
  56
  57 static const struct rpc_credops gss_credops;
  58 static const struct rpc_credops gss_nullops;
  59
  60 #ifdef RPC_DEBUG
  61 # define RPCDBG_FACILITY        RPCDBG_AUTH
  62 #endif
  63
  64 #define GSS_CRED_SLACK          1024
  65 /* length of a krb5 verifier (48), plus data added before arguments when
  66  * using integrity (two 4-byte integers): */
  67 #define GSS_VERF_SLACK          100
  68
  69 struct gss_auth {
  70         struct kref kref;
  71         struct rpc_auth rpc_auth;
  72         struct gss_api_mech *mech;
  73         enum rpc_gss_svc service;
  74         struct rpc_clnt *client;
  75         /*
  76          * There are two upcall pipes; dentry[1], named "gssd", is used
  77          * for the new text-based upcall; dentry[0] is named after the
  78          * mechanism (for example, "krb5") and exists for
  79          * backwards-compatibility with older gssd's.
  80          */
  81         struct dentry *dentry[2];
  82 };
  83
  84 /* pipe_version >= 0 if and only if someone has a pipe open. */
  85 static int pipe_version = -1;
  86 static atomic_t pipe_users = ATOMIC_INIT(0);
  87 static DEFINE_SPINLOCK(pipe_version_lock);
  88 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
  89 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
  90
  91 static void gss_free_ctx(struct gss_cl_ctx *);
  92 static const struct rpc_pipe_ops gss_upcall_ops_v0;
  93 static const struct rpc_pipe_ops gss_upcall_ops_v1;
  94
  95 static inline struct gss_cl_ctx *
  96 gss_get_ctx(struct gss_cl_ctx *ctx)
  97 {
  98         atomic_inc(&ctx->count);
  99         return ctx;
 100 }
 101
 102 static inline void
 103 gss_put_ctx(struct gss_cl_ctx *ctx)
 104 {
 105         if (atomic_dec_and_test(&ctx->count))
 106                 gss_free_ctx(ctx);
 107 }
 108
 109 /* gss_cred_set_ctx:
 110  * called by gss_upcall_callback and gss_create_upcall in order
 111  * to set the gss context. The actual exchange of an old context
 112  * and a new one is protected by the inode->i_lock.
 113  */
 114 static void
 115 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 116 {
 117         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 118
 119         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 120                 return;
 121         gss_get_ctx(ctx);
 122         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 123         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 124         smp_mb__before_clear_bit();
 125         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 126 }
 127
 128 static const void *
 129 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 130 {
 131         const void *q = (const void *)((const char *)p + len);
 132         if (unlikely(q > end || q < p))
 133                 return ERR_PTR(-EFAULT);
 134         memcpy(res, p, len);
 135         return q;
 136 }
 137
 138 static inline const void *
 139 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 140 {
 141         const void *q;
 142         unsigned int len;
 143
 144         p = simple_get_bytes(p, end, &len, sizeof(len));
 145         if (IS_ERR(p))
 146                 return p;
 147         q = (const void *)((const char *)p + len);
 148         if (unlikely(q > end || q < p))
 149                 return ERR_PTR(-EFAULT);
 150         dest->data = kmemdup(p, len, GFP_NOFS);
 151         if (unlikely(dest->data == NULL))
 152                 return ERR_PTR(-ENOMEM);
 153         dest->len = len;
 154         return q;
 155 }
 156
 157 static struct gss_cl_ctx *
 158 gss_cred_get_ctx(struct rpc_cred *cred)
 159 {
 160         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 161         struct gss_cl_ctx *ctx = NULL;
 162
 163         rcu_read_lock();
 164         if (gss_cred->gc_ctx)
 165                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 166         rcu_read_unlock();
 167         return ctx;
 168 }
 169
 170 static struct gss_cl_ctx *
 171 gss_alloc_context(void)
 172 {
 173         struct gss_cl_ctx *ctx;
 174
 175         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 176         if (ctx != NULL) {
 177                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 178                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 179                 spin_lock_init(&ctx->gc_seq_lock);
 180                 atomic_set(&ctx->count,1);
 181         }
 182         return ctx;
 183 }
 184
 185 #define GSSD_MIN_TIMEOUT (60 * 60)
 186 static const void *
 187 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 188 {
 189         const void *q;
 190         unsigned int seclen;
 191         unsigned int timeout;
 192         u32 window_size;
 193         int ret;
 194
 195         /* First unsigned int gives the lifetime (in seconds) of the cred */
 196         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 197         if (IS_ERR(p))
 198                 goto err;
 199         if (timeout == 0)
 200                 timeout = GSSD_MIN_TIMEOUT;
 201         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 202         /* Sequence number window. Determines the maximum number of simultaneous requests */
 203         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 204         if (IS_ERR(p))
 205                 goto err;
 206         ctx->gc_win = window_size;
 207         /* gssd signals an error by passing ctx->gc_win = 0: */
 208         if (ctx->gc_win == 0) {
 209                 /*
 210                  * in which case, p points to an error code. Anything other
 211                  * than -EKEYEXPIRED gets converted to -EACCES.
 212                  */
 213                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 214                 if (!IS_ERR(p))
 215                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 216                                                     ERR_PTR(-EACCES);
 217                 goto err;
 218         }
 219         /* copy the opaque wire context */
 220         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 221         if (IS_ERR(p))
 222                 goto err;
 223         /* import the opaque security context */
 224         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 225         if (IS_ERR(p))
 226                 goto err;
 227         q = (const void *)((const char *)p + seclen);
 228         if (unlikely(q > end || q < p)) {
 229                 p = ERR_PTR(-EFAULT);
 230                 goto err;
 231         }
 232         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 233         if (ret < 0) {
 234                 p = ERR_PTR(ret);
 235                 goto err;
 236         }
 237         return q;
 238 err:
 239         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 240         return p;
 241 }
 242
 243 #define UPCALL_BUF_LEN 128
 244
 245 struct gss_upcall_msg {
 246         atomic_t count;
 247         uid_t   uid;
 248         struct rpc_pipe_msg msg;
 249         struct list_head list;
 250         struct gss_auth *auth;
 251         struct rpc_inode *inode;
 252         struct rpc_wait_queue rpc_waitqueue;
 253         wait_queue_head_t waitqueue;
 254         struct gss_cl_ctx *ctx;
 255         char databuf[UPCALL_BUF_LEN];
 256 };
 257
 258 static int get_pipe_version(void)
 259 {
 260         int ret;
 261
 262         spin_lock(&pipe_version_lock);
 263         if (pipe_version >= 0) {
 264                 atomic_inc(&pipe_users);
 265                 ret = pipe_version;
 266         } else
 267                 ret = -EAGAIN;
 268         spin_unlock(&pipe_version_lock);
 269         return ret;
 270 }
 271
 272 static void put_pipe_version(void)
 273 {
 274         if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
 275                 pipe_version = -1;
 276                 spin_unlock(&pipe_version_lock);
 277         }
 278 }
 279
 280 static void
 281 gss_release_msg(struct gss_upcall_msg *gss_msg)
 282 {
 283         if (!atomic_dec_and_test(&gss_msg->count))
 284                 return;
 285         put_pipe_version();
 286         BUG_ON(!list_empty(&gss_msg->list));
 287         if (gss_msg->ctx != NULL)
 288                 gss_put_ctx(gss_msg->ctx);
 289         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 290         kfree(gss_msg);
 291 }
 292
 293 static struct gss_upcall_msg *
 294 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 295 {
 296         struct gss_upcall_msg *pos;
 297         list_for_each_entry(pos, &rpci->in_downcall, list) {
 298                 if (pos->uid != uid)
 299                         continue;
 300                 atomic_inc(&pos->count);
 301                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 302                 return pos;
 303         }
 304         dprintk("RPC:       gss_find_upcall found nothing\n");
 305         return NULL;
 306 }
 307
 308 /* Try to add an upcall to the pipefs queue.
 309  * If an upcall owned by our uid already exists, then we return a reference
 310  * to that upcall instead of adding the new upcall.
 311  */
 312 static inline struct gss_upcall_msg *
 313 gss_add_msg(struct gss_upcall_msg *gss_msg)
 314 {
 315         struct rpc_inode *rpci = gss_msg->inode;
 316         struct inode *inode = &rpci->vfs_inode;
 317         struct gss_upcall_msg *old;
 318
 319         spin_lock(&inode->i_lock);
 320         old = __gss_find_upcall(rpci, gss_msg->uid);
 321         if (old == NULL) {
 322                 atomic_inc(&gss_msg->count);
 323                 list_add(&gss_msg->list, &rpci->in_downcall);
 324         } else
 325                 gss_msg = old;
 326         spin_unlock(&inode->i_lock);
 327         return gss_msg;
 328 }
 329
 330 static void
 331 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 332 {
 333         list_del_init(&gss_msg->list);
 334         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 335         wake_up_all(&gss_msg->waitqueue);
 336         atomic_dec(&gss_msg->count);
 337 }
 338
 339 static void
 340 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 341 {
 342         struct inode *inode = &gss_msg->inode->vfs_inode;
 343
 344         if (list_empty(&gss_msg->list))
 345                 return;
 346         spin_lock(&inode->i_lock);
 347         if (!list_empty(&gss_msg->list))
 348                 __gss_unhash_msg(gss_msg);
 349         spin_unlock(&inode->i_lock);
 350 }
 351
 352 static void
 353 gss_upcall_callback(struct rpc_task *task)
 354 {
 355         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 356                         struct gss_cred, gc_base);
 357         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 358         struct inode *inode = &gss_msg->inode->vfs_inode;
 359
 360         spin_lock(&inode->i_lock);
 361         if (gss_msg->ctx)
 362                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 363         else
 364                 task->tk_status = gss_msg->msg.errno;
 365         gss_cred->gc_upcall = NULL;
 366         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 367         spin_unlock(&inode->i_lock);
 368         gss_release_msg(gss_msg);
 369 }
 370
 371 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 372 {
 373         gss_msg->msg.data = &gss_msg->uid;
 374         gss_msg->msg.len = sizeof(gss_msg->uid);
 375 }
 376
 377 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 378                                 struct rpc_clnt *clnt, int machine_cred)
 379 {
 380         char *p = gss_msg->databuf;
 381         int len = 0;
 382
 383         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
 384                                    gss_msg->auth->mech->gm_name,
 385                                    gss_msg->uid);
 386         p += gss_msg->msg.len;
 387         if (clnt->cl_principal) {
 388                 len = sprintf(p, "target=%s ", clnt->cl_principal);
 389                 p += len;
 390                 gss_msg->msg.len += len;
 391         }
 392         if (machine_cred) {
 393                 len = sprintf(p, "service=* ");
 394                 p += len;
 395                 gss_msg->msg.len += len;
 396         } else if (!strcmp(clnt->cl_program->name, "nfs4_cb")) {
 397                 len = sprintf(p, "service=nfs ");
 398                 p += len;
 399                 gss_msg->msg.len += len;
 400         }
 401         len = sprintf(p, "\n");
 402         gss_msg->msg.len += len;
 403
 404         gss_msg->msg.data = gss_msg->databuf;
 405         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
 406 }
 407
 408 static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
 409                                 struct rpc_clnt *clnt, int machine_cred)
 410 {
 411         if (pipe_version == 0)
 412                 gss_encode_v0_msg(gss_msg);
 413         else /* pipe_version == 1 */
 414                 gss_encode_v1_msg(gss_msg, clnt, machine_cred);
 415 }
 416
 417 static inline struct gss_upcall_msg *
 418 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid, struct rpc_clnt *clnt,
 419                 int machine_cred)
 420 {
 421         struct gss_upcall_msg *gss_msg;
 422         int vers;
 423
 424         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 425         if (gss_msg == NULL)
 426                 return ERR_PTR(-ENOMEM);
 427         vers = get_pipe_version();
 428         if (vers < 0) {
 429                 kfree(gss_msg);
 430                 return ERR_PTR(vers);
 431         }
 432         gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode);
 433         INIT_LIST_HEAD(&gss_msg->list);
 434         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 435         init_waitqueue_head(&gss_msg->waitqueue);
 436         atomic_set(&gss_msg->count, 1);
 437         gss_msg->uid = uid;
 438         gss_msg->auth = gss_auth;
 439         gss_encode_msg(gss_msg, clnt, machine_cred);
 440         return gss_msg;
 441 }
 442
 443 static struct gss_upcall_msg *
 444 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 445 {
 446         struct gss_cred *gss_cred = container_of(cred,
 447                         struct gss_cred, gc_base);
 448         struct gss_upcall_msg *gss_new, *gss_msg;
 449         uid_t uid = cred->cr_uid;
 450
 451         gss_new = gss_alloc_msg(gss_auth, uid, clnt, gss_cred->gc_machine_cred);
 452         if (IS_ERR(gss_new))
 453                 return gss_new;
 454         gss_msg = gss_add_msg(gss_new);
 455         if (gss_msg == gss_new) {
 456                 struct inode *inode = &gss_new->inode->vfs_inode;
 457                 int res = rpc_queue_upcall(inode, &gss_new->msg);
 458                 if (res) {
 459                         gss_unhash_msg(gss_new);
 460                         gss_msg = ERR_PTR(res);
 461                 }
 462         } else
 463                 gss_release_msg(gss_new);
 464         return gss_msg;
 465 }
 466
 467 static void warn_gssd(void)
 468 {
 469         static unsigned long ratelimit;
 470         unsigned long now = jiffies;
 471
 472         if (time_after(now, ratelimit)) {
 473                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 474                                 "Please check user daemon is running.\n");
 475                 ratelimit = now + 15*HZ;
 476         }
 477 }
 478
 479 static inline int
 480 gss_refresh_upcall(struct rpc_task *task)
 481 {
 482         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 483         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 484                         struct gss_auth, rpc_auth);
 485         struct gss_cred *gss_cred = container_of(cred,
 486                         struct gss_cred, gc_base);
 487         struct gss_upcall_msg *gss_msg;
 488         struct inode *inode;
 489         int err = 0;
 490
 491         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 492                                                                 cred->cr_uid);
 493         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 494         if (PTR_ERR(gss_msg) == -EAGAIN) {
 495                 /* XXX: warning on the first, under the assumption we
 496                  * shouldn't normally hit this case on a refresh. */
 497                 warn_gssd();
 498                 task->tk_timeout = 15*HZ;
 499                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 500                 return 0;
 501         }
 502         if (IS_ERR(gss_msg)) {
 503                 err = PTR_ERR(gss_msg);
 504                 goto out;
 505         }
 506         inode = &gss_msg->inode->vfs_inode;
 507         spin_lock(&inode->i_lock);
 508         if (gss_cred->gc_upcall != NULL)
 509                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 510         else if (gss_msg->ctx != NULL) {
 511                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
 512                 gss_cred->gc_upcall = NULL;
 513                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 514         } else if (gss_msg->msg.errno >= 0) {
 515                 task->tk_timeout = 0;
 516                 gss_cred->gc_upcall = gss_msg;
 517                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 518                 atomic_inc(&gss_msg->count);
 519                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 520         } else
 521                 err = gss_msg->msg.errno;
 522         spin_unlock(&inode->i_lock);
 523         gss_release_msg(gss_msg);
 524 out:
 525         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 526                         task->tk_pid, cred->cr_uid, err);
 527         return err;
 528 }
 529
 530 static inline int
 531 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 532 {
 533         struct inode *inode;
 534         struct rpc_cred *cred = &gss_cred->gc_base;
 535         struct gss_upcall_msg *gss_msg;
 536         DEFINE_WAIT(wait);
 537         int err = 0;
 538
 539         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 540 retry:
 541         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 542         if (PTR_ERR(gss_msg) == -EAGAIN) {
 543                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 544                                 pipe_version >= 0, 15*HZ);
 545                 if (err)
 546                         goto out;
 547                 if (pipe_version < 0)
 548                         warn_gssd();
 549                 goto retry;
 550         }
 551         if (IS_ERR(gss_msg)) {
 552                 err = PTR_ERR(gss_msg);
 553                 goto out;
 554         }
 555         inode = &gss_msg->inode->vfs_inode;
 556         for (;;) {
 557                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 558                 spin_lock(&inode->i_lock);
 559                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 560                         break;
 561                 }
 562                 spin_unlock(&inode->i_lock);
 563                 if (signalled()) {
 564                         err = -ERESTARTSYS;
 565                         goto out_intr;
 566                 }
 567                 schedule();
 568         }
 569         if (gss_msg->ctx)
 570                 gss_cred_set_ctx(cred, gss_msg->ctx);
 571         else
 572                 err = gss_msg->msg.errno;
 573         spin_unlock(&inode->i_lock);
 574 out_intr:
 575         finish_wait(&gss_msg->waitqueue, &wait);
 576         gss_release_msg(gss_msg);
 577 out:
 578         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 579                         cred->cr_uid, err);
 580         return err;
 581 }
 582
 583 static ssize_t
 584 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 585                 char __user *dst, size_t buflen)
 586 {
 587         char *data = (char *)msg->data + msg->copied;
 588         size_t mlen = min(msg->len, buflen);
 589         unsigned long left;
 590
 591         left = copy_to_user(dst, data, mlen);
 592         if (left == mlen) {
 593                 msg->errno = -EFAULT;
 594                 return -EFAULT;
 595         }
 596
 597         mlen -= left;
 598         msg->copied += mlen;
 599         msg->errno = 0;
 600         return mlen;
 601 }
 602
 603 #define MSG_BUF_MAXSIZE 1024
 604
 605 static ssize_t
 606 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 607 {
 608         const void *p, *end;
 609         void *buf;
 610         struct gss_upcall_msg *gss_msg;
 611         struct inode *inode = filp->f_path.dentry->d_inode;
 612         struct gss_cl_ctx *ctx;
 613         uid_t uid;
 614         ssize_t err = -EFBIG;
 615
 616         if (mlen > MSG_BUF_MAXSIZE)
 617                 goto out;
 618         err = -ENOMEM;
 619         buf = kmalloc(mlen, GFP_NOFS);
 620         if (!buf)
 621                 goto out;
 622
 623         err = -EFAULT;
 624         if (copy_from_user(buf, src, mlen))
 625                 goto err;
 626
 627         end = (const void *)((char *)buf + mlen);
 628         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 629         if (IS_ERR(p)) {
 630                 err = PTR_ERR(p);
 631                 goto err;
 632         }
 633
 634         err = -ENOMEM;
 635         ctx = gss_alloc_context();
 636         if (ctx == NULL)
 637                 goto err;
 638
 639         err = -ENOENT;
 640         /* Find a matching upcall */
 641         spin_lock(&inode->i_lock);
 642         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 643         if (gss_msg == NULL) {
 644                 spin_unlock(&inode->i_lock);
 645                 goto err_put_ctx;
 646         }
 647         list_del_init(&gss_msg->list);
 648         spin_unlock(&inode->i_lock);
 649
 650         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 651         if (IS_ERR(p)) {
 652                 err = PTR_ERR(p);
 653                 switch (err) {
 654                 case -EACCES:
 655                 case -EKEYEXPIRED:
 656                         gss_msg->msg.errno = err;
 657                         err = mlen;
 658                         break;
 659                 case -EFAULT:
 660                 case -ENOMEM:
 661                 case -EINVAL:
 662                 case -ENOSYS:
 663                         gss_msg->msg.errno = -EAGAIN;
 664                         break;
 665                 default:
 666                         printk(KERN_CRIT "%s: bad return from "
 667                                 "gss_fill_context: %zd\n", __func__, err);
 668                         BUG();
 669                 }
 670                 goto err_release_msg;
 671         }
 672         gss_msg->ctx = gss_get_ctx(ctx);
 673         err = mlen;
 674
 675 err_release_msg:
 676         spin_lock(&inode->i_lock);
 677         __gss_unhash_msg(gss_msg);
 678         spin_unlock(&inode->i_lock);
 679         gss_release_msg(gss_msg);
 680 err_put_ctx:
 681         gss_put_ctx(ctx);
 682 err:
 683         kfree(buf);
 684 out:
 685         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 686         return err;
 687 }
 688
 689 static int gss_pipe_open(struct inode *inode, int new_version)
 690 {
 691         int ret = 0;
 692
 693         spin_lock(&pipe_version_lock);
 694         if (pipe_version < 0) {
 695                 /* First open of any gss pipe determines the version: */
 696                 pipe_version = new_version;
 697                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 698                 wake_up(&pipe_version_waitqueue);
 699         } else if (pipe_version != new_version) {
 700                 /* Trying to open a pipe of a different version */
 701                 ret = -EBUSY;
 702                 goto out;
 703         }
 704         atomic_inc(&pipe_users);
 705 out:
 706         spin_unlock(&pipe_version_lock);
 707         return ret;
 708
 709 }
 710
 711 static int gss_pipe_open_v0(struct inode *inode)
 712 {
 713         return gss_pipe_open(inode, 0);
 714 }
 715
 716 static int gss_pipe_open_v1(struct inode *inode)
 717 {
 718         return gss_pipe_open(inode, 1);
 719 }
 720
 721 static void
 722 gss_pipe_release(struct inode *inode)
 723 {
 724         struct rpc_inode *rpci = RPC_I(inode);
 725         struct gss_upcall_msg *gss_msg;
 726
 727         spin_lock(&inode->i_lock);
 728         while (!list_empty(&rpci->in_downcall)) {
 729
 730                 gss_msg = list_entry(rpci->in_downcall.next,
 731                                 struct gss_upcall_msg, list);
 732                 gss_msg->msg.errno = -EPIPE;
 733                 atomic_inc(&gss_msg->count);
 734                 __gss_unhash_msg(gss_msg);
 735                 spin_unlock(&inode->i_lock);
 736                 gss_release_msg(gss_msg);
 737                 spin_lock(&inode->i_lock);
 738         }
 739         spin_unlock(&inode->i_lock);
 740
 741         put_pipe_version();
 742 }
 743
 744 static void
 745 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 746 {
 747         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 748
 749         if (msg->errno < 0) {
 750                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 751                                 gss_msg);
 752                 atomic_inc(&gss_msg->count);
 753                 gss_unhash_msg(gss_msg);
 754                 if (msg->errno == -ETIMEDOUT)
 755                         warn_gssd();
 756                 gss_release_msg(gss_msg);
 757         }
 758 }
 759
 760 /*
 761  * NOTE: we have the opportunity to use different
 762  * parameters based on the input flavor (which must be a pseudoflavor)
 763  */
 764 static struct rpc_auth *
 765 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 766 {
 767         struct gss_auth *gss_auth;
 768         struct rpc_auth * auth;
 769         int err = -ENOMEM; /* XXX? */
 770
 771         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 772
 773         if (!try_module_get(THIS_MODULE))
 774                 return ERR_PTR(err);
 775         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 776                 goto out_dec;
 777         gss_auth->client = clnt;
 778         err = -EINVAL;
 779         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 780         if (!gss_auth->mech) {
 781                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 782                                 __func__, flavor);
 783                 goto err_free;
 784         }
 785         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 786         if (gss_auth->service == 0)
 787                 goto err_put_mech;
 788         auth = &gss_auth->rpc_auth;
 789         auth->au_cslack = GSS_CRED_SLACK >> 2;
 790         auth->au_rslack = GSS_VERF_SLACK >> 2;
 791         auth->au_ops = &authgss_ops;
 792         auth->au_flavor = flavor;
 793         atomic_set(&auth->au_count, 1);
 794         kref_init(&gss_auth->kref);
 795
 796         /*
 797          * Note: if we created the old pipe first, then someone who
 798          * examined the directory at the right moment might conclude
 799          * that we supported only the old pipe.  So we instead create
 800          * the new pipe first.
 801          */
 802         gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry,
 803                                          "gssd",
 804                                          clnt, &gss_upcall_ops_v1,
 805                                          RPC_PIPE_WAIT_FOR_OPEN);
 806         if (IS_ERR(gss_auth->dentry[1])) {
 807                 err = PTR_ERR(gss_auth->dentry[1]);
 808                 goto err_put_mech;
 809         }
 810
 811         gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry,
 812                                          gss_auth->mech->gm_name,
 813                                          clnt, &gss_upcall_ops_v0,
 814                                          RPC_PIPE_WAIT_FOR_OPEN);
 815         if (IS_ERR(gss_auth->dentry[0])) {
 816                 err = PTR_ERR(gss_auth->dentry[0]);
 817                 goto err_unlink_pipe_1;
 818         }
 819         err = rpcauth_init_credcache(auth);
 820         if (err)
 821                 goto err_unlink_pipe_0;
 822
 823         return auth;
 824 err_unlink_pipe_0:
 825         rpc_unlink(gss_auth->dentry[0]);
 826 err_unlink_pipe_1:
 827         rpc_unlink(gss_auth->dentry[1]);
 828 err_put_mech:
 829         gss_mech_put(gss_auth->mech);
 830 err_free:
 831         kfree(gss_auth);
 832 out_dec:
 833         module_put(THIS_MODULE);
 834         return ERR_PTR(err);
 835 }
 836
 837 static void
 838 gss_free(struct gss_auth *gss_auth)
 839 {
 840         rpc_unlink(gss_auth->dentry[1]);
 841         rpc_unlink(gss_auth->dentry[0]);
 842         gss_mech_put(gss_auth->mech);
 843
 844         kfree(gss_auth);
 845         module_put(THIS_MODULE);
 846 }
 847
 848 static void
 849 gss_free_callback(struct kref *kref)
 850 {
 851         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 852
 853         gss_free(gss_auth);
 854 }
 855
 856 static void
 857 gss_destroy(struct rpc_auth *auth)
 858 {
 859         struct gss_auth *gss_auth;
 860
 861         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 862                         auth, auth->au_flavor);
 863
 864         rpcauth_destroy_credcache(auth);
 865
 866         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 867         kref_put(&gss_auth->kref, gss_free_callback);
 868 }
 869
 870 /*
 871  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 872  * to the server with the GSS control procedure field set to
 873  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 874  * all RPCSEC_GSS state associated with that context.
 875  */
 876 static int
 877 gss_destroying_context(struct rpc_cred *cred)
 878 {
 879         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 880         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 881         struct rpc_task *task;
 882
 883         if (gss_cred->gc_ctx == NULL ||
 884             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 885                 return 0;
 886
 887         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 888         cred->cr_ops = &gss_nullops;
 889
 890         /* Take a reference to ensure the cred will be destroyed either
 891          * by the RPC call or by the put_rpccred() below */
 892         get_rpccred(cred);
 893
 894         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 895         if (!IS_ERR(task))
 896                 rpc_put_task(task);
 897
 898         put_rpccred(cred);
 899         return 1;
 900 }
 901
 902 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 903  * to create a new cred or context, so they check that things have been
 904  * allocated before freeing them. */
 905 static void
 906 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 907 {
 908         dprintk("RPC:       gss_free_ctx\n");
 909
 910         kfree(ctx->gc_wire_ctx.data);
 911         kfree(ctx);
 912 }
 913
 914 static void
 915 gss_free_ctx_callback(struct rcu_head *head)
 916 {
 917         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 918         gss_do_free_ctx(ctx);
 919 }
 920
 921 static void
 922 gss_free_ctx(struct gss_cl_ctx *ctx)
 923 {
 924         struct gss_ctx *gc_gss_ctx;
 925
 926         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 927         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 928         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 929         if (gc_gss_ctx)
 930                 gss_delete_sec_context(&gc_gss_ctx);
 931 }
 932
 933 static void
 934 gss_free_cred(struct gss_cred *gss_cred)
 935 {
 936         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 937         kfree(gss_cred);
 938 }
 939
 940 static void
 941 gss_free_cred_callback(struct rcu_head *head)
 942 {
 943         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 944         gss_free_cred(gss_cred);
 945 }
 946
 947 static void
 948 gss_destroy_nullcred(struct rpc_cred *cred)
 949 {
 950         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 951         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 952         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 953
 954         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 955         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 956         if (ctx)
 957                 gss_put_ctx(ctx);
 958         kref_put(&gss_auth->kref, gss_free_callback);
 959 }
 960
 961 static void
 962 gss_destroy_cred(struct rpc_cred *cred)
 963 {
 964
 965         if (gss_destroying_context(cred))
 966                 return;
 967         gss_destroy_nullcred(cred);
 968 }
 969
 970 /*
 971  * Lookup RPCSEC_GSS cred for the current process
 972  */
 973 static struct rpc_cred *
 974 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 975 {
 976         return rpcauth_lookup_credcache(auth, acred, flags);
 977 }
 978
 979 static struct rpc_cred *
 980 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 981 {
 982         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 983         struct gss_cred *cred = NULL;
 984         int err = -ENOMEM;
 985
 986         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
 987                 acred->uid, auth->au_flavor);
 988
 989         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
 990                 goto out_err;
 991
 992         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
 993         /*
 994          * Note: in order to force a call to call_refresh(), we deliberately
 995          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 996          */
 997         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
 998         cred->gc_service = gss_auth->service;
 999         cred->gc_machine_cred = acred->machine_cred;
1000         kref_get(&gss_auth->kref);
1001         return &cred->gc_base;
1002
1003 out_err:
1004         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
1005         return ERR_PTR(err);
1006 }
1007
1008 static int
1009 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1010 {
1011         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1012         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1013         int err;
1014
1015         do {
1016                 err = gss_create_upcall(gss_auth, gss_cred);
1017         } while (err == -EAGAIN);
1018         return err;
1019 }
1020
1021 static int
1022 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1023 {
1024         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1025
1026         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1027                 goto out;
1028         /* Don't match with creds that have expired. */
1029         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1030                 return 0;
1031         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1032                 return 0;
1033 out:
1034         if (acred->machine_cred != gss_cred->gc_machine_cred)
1035                 return 0;
1036         return (rc->cr_uid == acred->uid);
1037 }
1038
1039 /*
1040 * Marshal credentials.
1041 * Maybe we should keep a cached credential for performance reasons.
1042 */
1043 static __be32 *
1044 gss_marshal(struct rpc_task *task, __be32 *p)
1045 {
1046         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1047         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1048                                                  gc_base);
1049         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1050         __be32          *cred_len;
1051         struct rpc_rqst *req = task->tk_rqstp;
1052         u32             maj_stat = 0;
1053         struct xdr_netobj mic;
1054         struct kvec     iov;
1055         struct xdr_buf  verf_buf;
1056
1057         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
1058
1059         *p++ = htonl(RPC_AUTH_GSS);
1060         cred_len = p++;
1061
1062         spin_lock(&ctx->gc_seq_lock);
1063         req->rq_seqno = ctx->gc_seq++;
1064         spin_unlock(&ctx->gc_seq_lock);
1065
1066         *p++ = htonl((u32) RPC_GSS_VERSION);
1067         *p++ = htonl((u32) ctx->gc_proc);
1068         *p++ = htonl((u32) req->rq_seqno);
1069         *p++ = htonl((u32) gss_cred->gc_service);
1070         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1071         *cred_len = htonl((p - (cred_len + 1)) << 2);
1072
1073         /* We compute the checksum for the verifier over the xdr-encoded bytes
1074          * starting with the xid and ending at the end of the credential: */
1075         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
1076                                         req->rq_snd_buf.head[0].iov_base);
1077         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1078         xdr_buf_from_iov(&iov, &verf_buf);
1079
1080         /* set verifier flavor*/
1081         *p++ = htonl(RPC_AUTH_GSS);
1082
1083         mic.data = (u8 *)(p + 1);
1084         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1085         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1086                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1087         } else if (maj_stat != 0) {
1088                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1089                 goto out_put_ctx;
1090         }
1091         p = xdr_encode_opaque(p, NULL, mic.len);
1092         gss_put_ctx(ctx);
1093         return p;
1094 out_put_ctx:
1095         gss_put_ctx(ctx);
1096         return NULL;
1097 }
1098
1099 static int gss_renew_cred(struct rpc_task *task)
1100 {
1101         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
1102         struct gss_cred *gss_cred = container_of(oldcred,
1103                                                  struct gss_cred,
1104                                                  gc_base);
1105         struct rpc_auth *auth = oldcred->cr_auth;
1106         struct auth_cred acred = {
1107                 .uid = oldcred->cr_uid,
1108                 .machine_cred = gss_cred->gc_machine_cred,
1109         };
1110         struct rpc_cred *new;
1111
1112         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1113         if (IS_ERR(new))
1114                 return PTR_ERR(new);
1115         task->tk_msg.rpc_cred = new;
1116         put_rpccred(oldcred);
1117         return 0;
1118 }
1119
1120 /*
1121 * Refresh credentials. XXX - finish
1122 */
1123 static int
1124 gss_refresh(struct rpc_task *task)
1125 {
1126         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1127         int ret = 0;
1128
1129         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1130                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1131                 ret = gss_renew_cred(task);
1132                 if (ret < 0)
1133                         goto out;
1134                 cred = task->tk_msg.rpc_cred;
1135         }
1136
1137         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1138                 ret = gss_refresh_upcall(task);
1139 out:
1140         return ret;
1141 }
1142
1143 /* Dummy refresh routine: used only when destroying the context */
1144 static int
1145 gss_refresh_null(struct rpc_task *task)
1146 {
1147         return -EACCES;
1148 }
1149
1150 static __be32 *
1151 gss_validate(struct rpc_task *task, __be32 *p)
1152 {
1153         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1154         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1155         __be32          seq;
1156         struct kvec     iov;
1157         struct xdr_buf  verf_buf;
1158         struct xdr_netobj mic;
1159         u32             flav,len;
1160         u32             maj_stat;
1161
1162         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
1163
1164         flav = ntohl(*p++);
1165         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1166                 goto out_bad;
1167         if (flav != RPC_AUTH_GSS)
1168                 goto out_bad;
1169         seq = htonl(task->tk_rqstp->rq_seqno);
1170         iov.iov_base = &seq;
1171         iov.iov_len = sizeof(seq);
1172         xdr_buf_from_iov(&iov, &verf_buf);
1173         mic.data = (u8 *)p;
1174         mic.len = len;
1175
1176         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1177         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1178                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1179         if (maj_stat) {
1180                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1181                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1182                 goto out_bad;
1183         }
1184         /* We leave it to unwrap to calculate au_rslack. For now we just
1185          * calculate the length of the verifier: */
1186         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1187         gss_put_ctx(ctx);
1188         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1189                         task->tk_pid);
1190         return p + XDR_QUADLEN(len);
1191 out_bad:
1192         gss_put_ctx(ctx);
1193         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1194         return NULL;
1195 }
1196
1197 static inline int
1198 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1199                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1200 {
1201         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1202         struct xdr_buf  integ_buf;
1203         __be32          *integ_len = NULL;
1204         struct xdr_netobj mic;
1205         u32             offset;
1206         __be32          *q;
1207         struct kvec     *iov;
1208         u32             maj_stat = 0;
1209         int             status = -EIO;
1210
1211         integ_len = p++;
1212         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1213         *p++ = htonl(rqstp->rq_seqno);
1214
1215         status = encode(rqstp, p, obj);
1216         if (status)
1217                 return status;
1218
1219         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1220                                 offset, snd_buf->len - offset))
1221                 return status;
1222         *integ_len = htonl(integ_buf.len);
1223
1224         /* guess whether we're in the head or the tail: */
1225         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1226                 iov = snd_buf->tail;
1227         else
1228                 iov = snd_buf->head;
1229         p = iov->iov_base + iov->iov_len;
1230         mic.data = (u8 *)(p + 1);
1231
1232         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1233         status = -EIO; /* XXX? */
1234         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1235                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1236         else if (maj_stat)
1237                 return status;
1238         q = xdr_encode_opaque(p, NULL, mic.len);
1239
1240         offset = (u8 *)q - (u8 *)p;
1241         iov->iov_len += offset;
1242         snd_buf->len += offset;
1243         return 0;
1244 }
1245
1246 static void
1247 priv_release_snd_buf(struct rpc_rqst *rqstp)
1248 {
1249         int i;
1250
1251         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1252                 __free_page(rqstp->rq_enc_pages[i]);
1253         kfree(rqstp->rq_enc_pages);
1254 }
1255
1256 static int
1257 alloc_enc_pages(struct rpc_rqst *rqstp)
1258 {
1259         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1260         int first, last, i;
1261
1262         if (snd_buf->page_len == 0) {
1263                 rqstp->rq_enc_pages_num = 0;
1264                 return 0;
1265         }
1266
1267         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1268         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1269         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1270         rqstp->rq_enc_pages
1271                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1272                                 GFP_NOFS);
1273         if (!rqstp->rq_enc_pages)
1274                 goto out;
1275         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1276                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1277                 if (rqstp->rq_enc_pages[i] == NULL)
1278                         goto out_free;
1279         }
1280         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1281         return 0;
1282 out_free:
1283         rqstp->rq_enc_pages_num = i;
1284         priv_release_snd_buf(rqstp);
1285 out:
1286         return -EAGAIN;
1287 }
1288
1289 static inline int
1290 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1291                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1292 {
1293         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1294         u32             offset;
1295         u32             maj_stat;
1296         int             status;
1297         __be32          *opaque_len;
1298         struct page     **inpages;
1299         int             first;
1300         int             pad;
1301         struct kvec     *iov;
1302         char            *tmp;
1303
1304         opaque_len = p++;
1305         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1306         *p++ = htonl(rqstp->rq_seqno);
1307
1308         status = encode(rqstp, p, obj);
1309         if (status)
1310                 return status;
1311
1312         status = alloc_enc_pages(rqstp);
1313         if (status)
1314                 return status;
1315         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1316         inpages = snd_buf->pages + first;
1317         snd_buf->pages = rqstp->rq_enc_pages;
1318         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1319         /* Give the tail its own page, in case we need extra space in the
1320          * head when wrapping: */
1321         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1322                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1323                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1324                 snd_buf->tail[0].iov_base = tmp;
1325         }
1326         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1327         /* RPC_SLACK_SPACE should prevent this ever happening: */
1328         BUG_ON(snd_buf->len > snd_buf->buflen);
1329         status = -EIO;
1330         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1331          * done anyway, so it's safe to put the request on the wire: */
1332         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1333                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1334         else if (maj_stat)
1335                 return status;
1336
1337         *opaque_len = htonl(snd_buf->len - offset);
1338         /* guess whether we're in the head or the tail: */
1339         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1340                 iov = snd_buf->tail;
1341         else
1342                 iov = snd_buf->head;
1343         p = iov->iov_base + iov->iov_len;
1344         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1345         memset(p, 0, pad);
1346         iov->iov_len += pad;
1347         snd_buf->len += pad;
1348
1349         return 0;
1350 }
1351
1352 static int
1353 gss_wrap_req(struct rpc_task *task,
1354              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1355 {
1356         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1357         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1358                         gc_base);
1359         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1360         int             status = -EIO;
1361
1362         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1363         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1364                 /* The spec seems a little ambiguous here, but I think that not
1365                  * wrapping context destruction requests makes the most sense.
1366                  */
1367                 status = encode(rqstp, p, obj);
1368                 goto out;
1369         }
1370         switch (gss_cred->gc_service) {
1371                 case RPC_GSS_SVC_NONE:
1372                         status = encode(rqstp, p, obj);
1373                         break;
1374                 case RPC_GSS_SVC_INTEGRITY:
1375                         status = gss_wrap_req_integ(cred, ctx, encode,
1376                                                                 rqstp, p, obj);
1377                         break;
1378                 case RPC_GSS_SVC_PRIVACY:
1379                         status = gss_wrap_req_priv(cred, ctx, encode,
1380                                         rqstp, p, obj);
1381                         break;
1382         }
1383 out:
1384         gss_put_ctx(ctx);
1385         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1386         return status;
1387 }
1388
1389 static inline int
1390 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1391                 struct rpc_rqst *rqstp, __be32 **p)
1392 {
1393         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1394         struct xdr_buf integ_buf;
1395         struct xdr_netobj mic;
1396         u32 data_offset, mic_offset;
1397         u32 integ_len;
1398         u32 maj_stat;
1399         int status = -EIO;
1400
1401         integ_len = ntohl(*(*p)++);
1402         if (integ_len & 3)
1403                 return status;
1404         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1405         mic_offset = integ_len + data_offset;
1406         if (mic_offset > rcv_buf->len)
1407                 return status;
1408         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1409                 return status;
1410
1411         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1412                                 mic_offset - data_offset))
1413                 return status;
1414
1415         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1416                 return status;
1417
1418         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1419         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1420                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1421         if (maj_stat != GSS_S_COMPLETE)
1422                 return status;
1423         return 0;
1424 }
1425
1426 static inline int
1427 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1428                 struct rpc_rqst *rqstp, __be32 **p)
1429 {
1430         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1431         u32 offset;
1432         u32 opaque_len;
1433         u32 maj_stat;
1434         int status = -EIO;
1435
1436         opaque_len = ntohl(*(*p)++);
1437         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1438         if (offset + opaque_len > rcv_buf->len)
1439                 return status;
1440         /* remove padding: */
1441         rcv_buf->len = offset + opaque_len;
1442
1443         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1444         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1445                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1446         if (maj_stat != GSS_S_COMPLETE)
1447                 return status;
1448         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1449                 return status;
1450
1451         return 0;
1452 }
1453
1454
1455 static int
1456 gss_unwrap_resp(struct rpc_task *task,
1457                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1458 {
1459         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1460         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1461                         gc_base);
1462         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1463         __be32          *savedp = p;
1464         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1465         int             savedlen = head->iov_len;
1466         int             status = -EIO;
1467
1468         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1469                 goto out_decode;
1470         switch (gss_cred->gc_service) {
1471                 case RPC_GSS_SVC_NONE:
1472                         break;
1473                 case RPC_GSS_SVC_INTEGRITY:
1474                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1475                         if (status)
1476                                 goto out;
1477                         break;
1478                 case RPC_GSS_SVC_PRIVACY:
1479                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1480                         if (status)
1481                                 goto out;
1482                         break;
1483         }
1484         /* take into account extra slack for integrity and privacy cases: */
1485         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1486                                                 + (savedlen - head->iov_len);
1487 out_decode:
1488         status = decode(rqstp, p, obj);
1489 out:
1490         gss_put_ctx(ctx);
1491         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1492                         status);
1493         return status;
1494 }
1495
1496 static const struct rpc_authops authgss_ops = {
1497         .owner          = THIS_MODULE,
1498         .au_flavor      = RPC_AUTH_GSS,
1499         .au_name        = "RPCSEC_GSS",
1500         .create         = gss_create,
1501         .destroy        = gss_destroy,
1502         .lookup_cred    = gss_lookup_cred,
1503         .crcreate       = gss_create_cred
1504 };
1505
1506 static const struct rpc_credops gss_credops = {
1507         .cr_name        = "AUTH_GSS",
1508         .crdestroy      = gss_destroy_cred,
1509         .cr_init        = gss_cred_init,
1510         .crbind         = rpcauth_generic_bind_cred,
1511         .crmatch        = gss_match,
1512         .crmarshal      = gss_marshal,
1513         .crrefresh      = gss_refresh,
1514         .crvalidate     = gss_validate,
1515         .crwrap_req     = gss_wrap_req,
1516         .crunwrap_resp  = gss_unwrap_resp,
1517 };
1518
1519 static const struct rpc_credops gss_nullops = {
1520         .cr_name        = "AUTH_GSS",
1521         .crdestroy      = gss_destroy_nullcred,
1522         .crbind         = rpcauth_generic_bind_cred,
1523         .crmatch        = gss_match,
1524         .crmarshal      = gss_marshal,
1525         .crrefresh      = gss_refresh_null,
1526         .crvalidate     = gss_validate,
1527         .crwrap_req     = gss_wrap_req,
1528         .crunwrap_resp  = gss_unwrap_resp,
1529 };
1530
1531 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1532         .upcall         = gss_pipe_upcall,
1533         .downcall       = gss_pipe_downcall,
1534         .destroy_msg    = gss_pipe_destroy_msg,
1535         .open_pipe      = gss_pipe_open_v0,
1536         .release_pipe   = gss_pipe_release,
1537 };
1538
1539 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1540         .upcall         = gss_pipe_upcall,
1541         .downcall       = gss_pipe_downcall,
1542         .destroy_msg    = gss_pipe_destroy_msg,
1543         .open_pipe      = gss_pipe_open_v1,
1544         .release_pipe   = gss_pipe_release,
1545 };
1546
1547 /*
1548  * Initialize RPCSEC_GSS module
1549  */
1550 static int __init init_rpcsec_gss(void)
1551 {
1552         int err = 0;
1553
1554         err = rpcauth_register(&authgss_ops);
1555         if (err)
1556                 goto out;
1557         err = gss_svc_init();
1558         if (err)
1559                 goto out_unregister;
1560         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1561         return 0;
1562 out_unregister:
1563         rpcauth_unregister(&authgss_ops);
1564 out:
1565         return err;
1566 }
1567
1568 static void __exit exit_rpcsec_gss(void)
1569 {
1570         gss_svc_shutdown();
1571         rpcauth_unregister(&authgss_ops);
1572         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1573 }
1574
1575 MODULE_LICENSE("GPL");
1576 module_init(init_rpcsec_gss)
1577 module_exit(exit_rpcsec_gss)