net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * $Id$
  38  */
  39
  40
  41 #include <linux/module.h>
  42 #include <linux/init.h>
  43 #include <linux/types.h>
  44 #include <linux/slab.h>
  45 #include <linux/socket.h>
  46 #include <linux/in.h>
  47 #include <linux/sched.h>
  48 #include <linux/sunrpc/clnt.h>
  49 #include <linux/sunrpc/auth.h>
  50 #include <linux/sunrpc/auth_gss.h>
  51 #include <linux/sunrpc/svcauth_gss.h>
  52 #include <linux/sunrpc/gss_err.h>
  53 #include <linux/workqueue.h>
  54 #include <linux/sunrpc/rpc_pipe_fs.h>
  55 #include <linux/sunrpc/gss_api.h>
  56 #include <asm/uaccess.h>
  57
  58 static struct rpc_authops authgss_ops;
  59
  60 static struct rpc_credops gss_credops;
  61
  62 #ifdef RPC_DEBUG
  63 # define RPCDBG_FACILITY        RPCDBG_AUTH
  64 #endif
  65
  66 #define NFS_NGROUPS     16
  67
  68 #define GSS_CRED_EXPIRE         (60 * HZ)       /* XXX: reasonable? */
  69 #define GSS_CRED_SLACK          1024            /* XXX: unused */
  70 /* length of a krb5 verifier (48), plus data added before arguments when
  71  * using integrity (two 4-byte integers): */
  72 #define GSS_VERF_SLACK          56
  73
  74 /* XXX this define must match the gssd define
  75 * as it is passed to gssd to signal the use of
  76 * machine creds should be part of the shared rpc interface */
  77
  78 #define CA_RUN_AS_MACHINE  0x00000200
  79
  80 /* dump the buffer in `emacs-hexl' style */
  81 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
  82
  83 static DEFINE_RWLOCK(gss_ctx_lock);
  84
  85 struct gss_auth {
  86         struct rpc_auth rpc_auth;
  87         struct gss_api_mech *mech;
  88         enum rpc_gss_svc service;
  89         struct list_head upcalls;
  90         struct rpc_clnt *client;
  91         struct dentry *dentry;
  92         char path[48];
  93         spinlock_t lock;
  94 };
  95
  96 static void gss_destroy_ctx(struct gss_cl_ctx *);
  97 static struct rpc_pipe_ops gss_upcall_ops;
  98
  99 void
 100 print_hexl(u32 *p, u_int length, u_int offset)
 101 {
 102         u_int i, j, jm;
 103         u8 c, *cp;
 104
 105         dprintk("RPC: print_hexl: length %d\n",length);
 106         dprintk("\n");
 107         cp = (u8 *) p;
 108
 109         for (i = 0; i < length; i += 0x10) {
 110                 dprintk("  %04x: ", (u_int)(i + offset));
 111                 jm = length - i;
 112                 jm = jm > 16 ? 16 : jm;
 113
 114                 for (j = 0; j < jm; j++) {
 115                         if ((j % 2) == 1)
 116                                 dprintk("%02x ", (u_int)cp[i+j]);
 117                         else
 118                                 dprintk("%02x", (u_int)cp[i+j]);
 119                 }
 120                 for (; j < 16; j++) {
 121                         if ((j % 2) == 1)
 122                                 dprintk("   ");
 123                         else
 124                                 dprintk("  ");
 125                 }
 126                 dprintk(" ");
 127
 128                 for (j = 0; j < jm; j++) {
 129                         c = cp[i+j];
 130                         c = isprint(c) ? c : '.';
 131                         dprintk("%c", c);
 132                 }
 133                 dprintk("\n");
 134         }
 135 }
 136
 137 EXPORT_SYMBOL(print_hexl);
 138
 139 static inline struct gss_cl_ctx *
 140 gss_get_ctx(struct gss_cl_ctx *ctx)
 141 {
 142         atomic_inc(&ctx->count);
 143         return ctx;
 144 }
 145
 146 static inline void
 147 gss_put_ctx(struct gss_cl_ctx *ctx)
 148 {
 149         if (atomic_dec_and_test(&ctx->count))
 150                 gss_destroy_ctx(ctx);
 151 }
 152
 153 static void
 154 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 155 {
 156         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 157         struct gss_cl_ctx *old;
 158         write_lock(&gss_ctx_lock);
 159         old = gss_cred->gc_ctx;
 160         gss_cred->gc_ctx = ctx;
 161         cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
 162         write_unlock(&gss_ctx_lock);
 163         if (old)
 164                 gss_put_ctx(old);
 165 }
 166
 167 static int
 168 gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
 169 {
 170         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 171         int res = 0;
 172
 173         read_lock(&gss_ctx_lock);
 174         if ((cred->cr_flags & RPCAUTH_CRED_UPTODATE) && gss_cred->gc_ctx)
 175                 res = 1;
 176         read_unlock(&gss_ctx_lock);
 177         return res;
 178 }
 179
 180 static const void *
 181 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 182 {
 183         const void *q = (const void *)((const char *)p + len);
 184         if (unlikely(q > end || q < p))
 185                 return ERR_PTR(-EFAULT);
 186         memcpy(res, p, len);
 187         return q;
 188 }
 189
 190 static inline const void *
 191 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 192 {
 193         const void *q;
 194         unsigned int len;
 195
 196         p = simple_get_bytes(p, end, &len, sizeof(len));
 197         if (IS_ERR(p))
 198                 return p;
 199         q = (const void *)((const char *)p + len);
 200         if (unlikely(q > end || q < p))
 201                 return ERR_PTR(-EFAULT);
 202         dest->data = kmalloc(len, GFP_KERNEL);
 203         if (unlikely(dest->data == NULL))
 204                 return ERR_PTR(-ENOMEM);
 205         dest->len = len;
 206         memcpy(dest->data, p, len);
 207         return q;
 208 }
 209
 210 static struct gss_cl_ctx *
 211 gss_cred_get_ctx(struct rpc_cred *cred)
 212 {
 213         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 214         struct gss_cl_ctx *ctx = NULL;
 215
 216         read_lock(&gss_ctx_lock);
 217         if (gss_cred->gc_ctx)
 218                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 219         read_unlock(&gss_ctx_lock);
 220         return ctx;
 221 }
 222
 223 static struct gss_cl_ctx *
 224 gss_alloc_context(void)
 225 {
 226         struct gss_cl_ctx *ctx;
 227
 228         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
 229         if (ctx != NULL) {
 230                 memset(ctx, 0, sizeof(*ctx));
 231                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 232                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 233                 spin_lock_init(&ctx->gc_seq_lock);
 234                 atomic_set(&ctx->count,1);
 235         }
 236         return ctx;
 237 }
 238
 239 #define GSSD_MIN_TIMEOUT (60 * 60)
 240 static const void *
 241 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 242 {
 243         const void *q;
 244         unsigned int seclen;
 245         unsigned int timeout;
 246         u32 window_size;
 247         int ret;
 248
 249         /* First unsigned int gives the lifetime (in seconds) of the cred */
 250         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 251         if (IS_ERR(p))
 252                 goto err;
 253         if (timeout == 0)
 254                 timeout = GSSD_MIN_TIMEOUT;
 255         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 256         /* Sequence number window. Determines the maximum number of simultaneous requests */
 257         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 258         if (IS_ERR(p))
 259                 goto err;
 260         ctx->gc_win = window_size;
 261         /* gssd signals an error by passing ctx->gc_win = 0: */
 262         if (ctx->gc_win == 0) {
 263                 /* in which case, p points to  an error code which we ignore */
 264                 p = ERR_PTR(-EACCES);
 265                 goto err;
 266         }
 267         /* copy the opaque wire context */
 268         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 269         if (IS_ERR(p))
 270                 goto err;
 271         /* import the opaque security context */
 272         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 273         if (IS_ERR(p))
 274                 goto err;
 275         q = (const void *)((const char *)p + seclen);
 276         if (unlikely(q > end || q < p)) {
 277                 p = ERR_PTR(-EFAULT);
 278                 goto err;
 279         }
 280         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
 281         if (ret < 0) {
 282                 p = ERR_PTR(ret);
 283                 goto err;
 284         }
 285         return q;
 286 err:
 287         dprintk("RPC:      gss_fill_context returning %ld\n", -PTR_ERR(p));
 288         return p;
 289 }
 290
 291
 292 struct gss_upcall_msg {
 293         atomic_t count;
 294         uid_t   uid;
 295         struct rpc_pipe_msg msg;
 296         struct list_head list;
 297         struct gss_auth *auth;
 298         struct rpc_wait_queue rpc_waitqueue;
 299         wait_queue_head_t waitqueue;
 300         struct gss_cl_ctx *ctx;
 301 };
 302
 303 static void
 304 gss_release_msg(struct gss_upcall_msg *gss_msg)
 305 {
 306         if (!atomic_dec_and_test(&gss_msg->count))
 307                 return;
 308         BUG_ON(!list_empty(&gss_msg->list));
 309         if (gss_msg->ctx != NULL)
 310                 gss_put_ctx(gss_msg->ctx);
 311         kfree(gss_msg);
 312 }
 313
 314 static struct gss_upcall_msg *
 315 __gss_find_upcall(struct gss_auth *gss_auth, uid_t uid)
 316 {
 317         struct gss_upcall_msg *pos;
 318         list_for_each_entry(pos, &gss_auth->upcalls, list) {
 319                 if (pos->uid != uid)
 320                         continue;
 321                 atomic_inc(&pos->count);
 322                 dprintk("RPC:      gss_find_upcall found msg %p\n", pos);
 323                 return pos;
 324         }
 325         dprintk("RPC:      gss_find_upcall found nothing\n");
 326         return NULL;
 327 }
 328
 329 /* Try to add a upcall to the pipefs queue.
 330  * If an upcall owned by our uid already exists, then we return a reference
 331  * to that upcall instead of adding the new upcall.
 332  */
 333 static inline struct gss_upcall_msg *
 334 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 335 {
 336         struct gss_upcall_msg *old;
 337
 338         spin_lock(&gss_auth->lock);
 339         old = __gss_find_upcall(gss_auth, gss_msg->uid);
 340         if (old == NULL) {
 341                 atomic_inc(&gss_msg->count);
 342                 list_add(&gss_msg->list, &gss_auth->upcalls);
 343         } else
 344                 gss_msg = old;
 345         spin_unlock(&gss_auth->lock);
 346         return gss_msg;
 347 }
 348
 349 static void
 350 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 351 {
 352         if (list_empty(&gss_msg->list))
 353                 return;
 354         list_del_init(&gss_msg->list);
 355         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 356         wake_up_all(&gss_msg->waitqueue);
 357         atomic_dec(&gss_msg->count);
 358 }
 359
 360 static void
 361 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 362 {
 363         struct gss_auth *gss_auth = gss_msg->auth;
 364
 365         spin_lock(&gss_auth->lock);
 366         __gss_unhash_msg(gss_msg);
 367         spin_unlock(&gss_auth->lock);
 368 }
 369
 370 static void
 371 gss_upcall_callback(struct rpc_task *task)
 372 {
 373         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 374                         struct gss_cred, gc_base);
 375         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 376
 377         BUG_ON(gss_msg == NULL);
 378         if (gss_msg->ctx)
 379                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx));
 380         else
 381                 task->tk_status = gss_msg->msg.errno;
 382         spin_lock(&gss_msg->auth->lock);
 383         gss_cred->gc_upcall = NULL;
 384         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 385         spin_unlock(&gss_msg->auth->lock);
 386         gss_release_msg(gss_msg);
 387 }
 388
 389 static inline struct gss_upcall_msg *
 390 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
 391 {
 392         struct gss_upcall_msg *gss_msg;
 393
 394         gss_msg = kmalloc(sizeof(*gss_msg), GFP_KERNEL);
 395         if (gss_msg != NULL) {
 396                 memset(gss_msg, 0, sizeof(*gss_msg));
 397                 INIT_LIST_HEAD(&gss_msg->list);
 398                 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 399                 init_waitqueue_head(&gss_msg->waitqueue);
 400                 atomic_set(&gss_msg->count, 1);
 401                 gss_msg->msg.data = &gss_msg->uid;
 402                 gss_msg->msg.len = sizeof(gss_msg->uid);
 403                 gss_msg->uid = uid;
 404                 gss_msg->auth = gss_auth;
 405         }
 406         return gss_msg;
 407 }
 408
 409 static struct gss_upcall_msg *
 410 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 411 {
 412         struct gss_upcall_msg *gss_new, *gss_msg;
 413
 414         gss_new = gss_alloc_msg(gss_auth, cred->cr_uid);
 415         if (gss_new == NULL)
 416                 return ERR_PTR(-ENOMEM);
 417         gss_msg = gss_add_msg(gss_auth, gss_new);
 418         if (gss_msg == gss_new) {
 419                 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
 420                 if (res) {
 421                         gss_unhash_msg(gss_new);
 422                         gss_msg = ERR_PTR(res);
 423                 }
 424         } else
 425                 gss_release_msg(gss_new);
 426         return gss_msg;
 427 }
 428
 429 static inline int
 430 gss_refresh_upcall(struct rpc_task *task)
 431 {
 432         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 433         struct gss_auth *gss_auth = container_of(task->tk_client->cl_auth,
 434                         struct gss_auth, rpc_auth);
 435         struct gss_cred *gss_cred = container_of(cred,
 436                         struct gss_cred, gc_base);
 437         struct gss_upcall_msg *gss_msg;
 438         int err = 0;
 439
 440         dprintk("RPC: %4u gss_refresh_upcall for uid %u\n", task->tk_pid, cred->cr_uid);
 441         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 442         if (IS_ERR(gss_msg)) {
 443                 err = PTR_ERR(gss_msg);
 444                 goto out;
 445         }
 446         spin_lock(&gss_auth->lock);
 447         if (gss_cred->gc_upcall != NULL)
 448                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL);
 449         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 450                 task->tk_timeout = 0;
 451                 gss_cred->gc_upcall = gss_msg;
 452                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 453                 atomic_inc(&gss_msg->count);
 454                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL);
 455         } else
 456                 err = gss_msg->msg.errno;
 457         spin_unlock(&gss_auth->lock);
 458         gss_release_msg(gss_msg);
 459 out:
 460         dprintk("RPC: %4u gss_refresh_upcall for uid %u result %d\n", task->tk_pid,
 461                         cred->cr_uid, err);
 462         return err;
 463 }
 464
 465 static inline int
 466 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 467 {
 468         struct rpc_cred *cred = &gss_cred->gc_base;
 469         struct gss_upcall_msg *gss_msg;
 470         DEFINE_WAIT(wait);
 471         int err = 0;
 472
 473         dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid);
 474         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 475         if (IS_ERR(gss_msg)) {
 476                 err = PTR_ERR(gss_msg);
 477                 goto out;
 478         }
 479         for (;;) {
 480                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 481                 spin_lock(&gss_auth->lock);
 482                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 483                         spin_unlock(&gss_auth->lock);
 484                         break;
 485                 }
 486                 spin_unlock(&gss_auth->lock);
 487                 if (signalled()) {
 488                         err = -ERESTARTSYS;
 489                         goto out_intr;
 490                 }
 491                 schedule();
 492         }
 493         if (gss_msg->ctx)
 494                 gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));
 495         else
 496                 err = gss_msg->msg.errno;
 497 out_intr:
 498         finish_wait(&gss_msg->waitqueue, &wait);
 499         gss_release_msg(gss_msg);
 500 out:
 501         dprintk("RPC: gss_create_upcall for uid %u result %d\n", cred->cr_uid, err);
 502         return err;
 503 }
 504
 505 static ssize_t
 506 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 507                 char __user *dst, size_t buflen)
 508 {
 509         char *data = (char *)msg->data + msg->copied;
 510         ssize_t mlen = msg->len;
 511         ssize_t left;
 512
 513         if (mlen > buflen)
 514                 mlen = buflen;
 515         left = copy_to_user(dst, data, mlen);
 516         if (left < 0) {
 517                 msg->errno = left;
 518                 return left;
 519         }
 520         mlen -= left;
 521         msg->copied += mlen;
 522         msg->errno = 0;
 523         return mlen;
 524 }
 525
 526 #define MSG_BUF_MAXSIZE 1024
 527
 528 static ssize_t
 529 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 530 {
 531         const void *p, *end;
 532         void *buf;
 533         struct rpc_clnt *clnt;
 534         struct gss_auth *gss_auth;
 535         struct rpc_cred *cred;
 536         struct gss_upcall_msg *gss_msg;
 537         struct gss_cl_ctx *ctx;
 538         uid_t uid;
 539         int err = -EFBIG;
 540
 541         if (mlen > MSG_BUF_MAXSIZE)
 542                 goto out;
 543         err = -ENOMEM;
 544         buf = kmalloc(mlen, GFP_KERNEL);
 545         if (!buf)
 546                 goto out;
 547
 548         clnt = RPC_I(filp->f_dentry->d_inode)->private;
 549         err = -EFAULT;
 550         if (copy_from_user(buf, src, mlen))
 551                 goto err;
 552
 553         end = (const void *)((char *)buf + mlen);
 554         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 555         if (IS_ERR(p)) {
 556                 err = PTR_ERR(p);
 557                 goto err;
 558         }
 559
 560         err = -ENOMEM;
 561         ctx = gss_alloc_context();
 562         if (ctx == NULL)
 563                 goto err;
 564         err = 0;
 565         gss_auth = container_of(clnt->cl_auth, struct gss_auth, rpc_auth);
 566         p = gss_fill_context(p, end, ctx, gss_auth->mech);
 567         if (IS_ERR(p)) {
 568                 err = PTR_ERR(p);
 569                 if (err != -EACCES)
 570                         goto err_put_ctx;
 571         }
 572         spin_lock(&gss_auth->lock);
 573         gss_msg = __gss_find_upcall(gss_auth, uid);
 574         if (gss_msg) {
 575                 if (err == 0 && gss_msg->ctx == NULL)
 576                         gss_msg->ctx = gss_get_ctx(ctx);
 577                 gss_msg->msg.errno = err;
 578                 __gss_unhash_msg(gss_msg);
 579                 spin_unlock(&gss_auth->lock);
 580                 gss_release_msg(gss_msg);
 581         } else {
 582                 struct auth_cred acred = { .uid = uid };
 583                 spin_unlock(&gss_auth->lock);
 584                 cred = rpcauth_lookup_credcache(clnt->cl_auth, &acred, 0);
 585                 if (IS_ERR(cred)) {
 586                         err = PTR_ERR(cred);
 587                         goto err_put_ctx;
 588                 }
 589                 gss_cred_set_ctx(cred, gss_get_ctx(ctx));
 590         }
 591         gss_put_ctx(ctx);
 592         kfree(buf);
 593         dprintk("RPC:      gss_pipe_downcall returning length %Zu\n", mlen);
 594         return mlen;
 595 err_put_ctx:
 596         gss_put_ctx(ctx);
 597 err:
 598         kfree(buf);
 599 out:
 600         dprintk("RPC:      gss_pipe_downcall returning %d\n", err);
 601         return err;
 602 }
 603
 604 static void
 605 gss_pipe_release(struct inode *inode)
 606 {
 607         struct rpc_inode *rpci = RPC_I(inode);
 608         struct rpc_clnt *clnt;
 609         struct rpc_auth *auth;
 610         struct gss_auth *gss_auth;
 611
 612         clnt = rpci->private;
 613         auth = clnt->cl_auth;
 614         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 615         spin_lock(&gss_auth->lock);
 616         while (!list_empty(&gss_auth->upcalls)) {
 617                 struct gss_upcall_msg *gss_msg;
 618
 619                 gss_msg = list_entry(gss_auth->upcalls.next,
 620                                 struct gss_upcall_msg, list);
 621                 gss_msg->msg.errno = -EPIPE;
 622                 atomic_inc(&gss_msg->count);
 623                 __gss_unhash_msg(gss_msg);
 624                 spin_unlock(&gss_auth->lock);
 625                 gss_release_msg(gss_msg);
 626                 spin_lock(&gss_auth->lock);
 627         }
 628         spin_unlock(&gss_auth->lock);
 629 }
 630
 631 static void
 632 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 633 {
 634         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 635         static unsigned long ratelimit;
 636
 637         if (msg->errno < 0) {
 638                 dprintk("RPC:      gss_pipe_destroy_msg releasing msg %p\n",
 639                                 gss_msg);
 640                 atomic_inc(&gss_msg->count);
 641                 gss_unhash_msg(gss_msg);
 642                 if (msg->errno == -ETIMEDOUT || msg->errno == -EPIPE) {
 643                         unsigned long now = jiffies;
 644                         if (time_after(now, ratelimit)) {
 645                                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 646                                                     "Please check user daemon is running!\n");
 647                                 ratelimit = now + 15*HZ;
 648                         }
 649                 }
 650                 gss_release_msg(gss_msg);
 651         }
 652 }
 653
 654 /*
 655  * NOTE: we have the opportunity to use different
 656  * parameters based on the input flavor (which must be a pseudoflavor)
 657  */
 658 static struct rpc_auth *
 659 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 660 {
 661         struct gss_auth *gss_auth;
 662         struct rpc_auth * auth;
 663         int err = -ENOMEM; /* XXX? */
 664
 665         dprintk("RPC:      creating GSS authenticator for client %p\n",clnt);
 666
 667         if (!try_module_get(THIS_MODULE))
 668                 return ERR_PTR(err);
 669         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 670                 goto out_dec;
 671         gss_auth->client = clnt;
 672         err = -EINVAL;
 673         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 674         if (!gss_auth->mech) {
 675                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
 676                                 __FUNCTION__, flavor);
 677                 goto err_free;
 678         }
 679         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 680         if (gss_auth->service == 0)
 681                 goto err_put_mech;
 682         INIT_LIST_HEAD(&gss_auth->upcalls);
 683         spin_lock_init(&gss_auth->lock);
 684         auth = &gss_auth->rpc_auth;
 685         auth->au_cslack = GSS_CRED_SLACK >> 2;
 686         auth->au_rslack = GSS_VERF_SLACK >> 2;
 687         auth->au_ops = &authgss_ops;
 688         auth->au_flavor = flavor;
 689         atomic_set(&auth->au_count, 1);
 690
 691         err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE);
 692         if (err)
 693                 goto err_put_mech;
 694
 695         snprintf(gss_auth->path, sizeof(gss_auth->path), "%s/%s",
 696                         clnt->cl_pathname,
 697                         gss_auth->mech->gm_name);
 698         gss_auth->dentry = rpc_mkpipe(gss_auth->path, clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 699         if (IS_ERR(gss_auth->dentry)) {
 700                 err = PTR_ERR(gss_auth->dentry);
 701                 goto err_put_mech;
 702         }
 703
 704         return auth;
 705 err_put_mech:
 706         gss_mech_put(gss_auth->mech);
 707 err_free:
 708         kfree(gss_auth);
 709 out_dec:
 710         module_put(THIS_MODULE);
 711         return ERR_PTR(err);
 712 }
 713
 714 static void
 715 gss_destroy(struct rpc_auth *auth)
 716 {
 717         struct gss_auth *gss_auth;
 718
 719         dprintk("RPC:      destroying GSS authenticator %p flavor %d\n",
 720                 auth, auth->au_flavor);
 721
 722         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 723         rpc_unlink(gss_auth->path);
 724         gss_mech_put(gss_auth->mech);
 725
 726         rpcauth_free_credcache(auth);
 727         kfree(gss_auth);
 728         module_put(THIS_MODULE);
 729 }
 730
 731 /* gss_destroy_cred (and gss_destroy_ctx) are used to clean up after failure
 732  * to create a new cred or context, so they check that things have been
 733  * allocated before freeing them. */
 734 static void
 735 gss_destroy_ctx(struct gss_cl_ctx *ctx)
 736 {
 737         dprintk("RPC:      gss_destroy_ctx\n");
 738
 739         if (ctx->gc_gss_ctx)
 740                 gss_delete_sec_context(&ctx->gc_gss_ctx);
 741
 742         kfree(ctx->gc_wire_ctx.data);
 743         kfree(ctx);
 744 }
 745
 746 static void
 747 gss_destroy_cred(struct rpc_cred *rc)
 748 {
 749         struct gss_cred *cred = container_of(rc, struct gss_cred, gc_base);
 750
 751         dprintk("RPC:      gss_destroy_cred \n");
 752
 753         if (cred->gc_ctx)
 754                 gss_put_ctx(cred->gc_ctx);
 755         kfree(cred);
 756 }
 757
 758 /*
 759  * Lookup RPCSEC_GSS cred for the current process
 760  */
 761 static struct rpc_cred *
 762 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int taskflags)
 763 {
 764         return rpcauth_lookup_credcache(auth, acred, taskflags);
 765 }
 766
 767 static struct rpc_cred *
 768 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int taskflags)
 769 {
 770         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 771         struct gss_cred *cred = NULL;
 772         int err = -ENOMEM;
 773
 774         dprintk("RPC:      gss_create_cred for uid %d, flavor %d\n",
 775                 acred->uid, auth->au_flavor);
 776
 777         if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL)))
 778                 goto out_err;
 779
 780         memset(cred, 0, sizeof(*cred));
 781         atomic_set(&cred->gc_count, 1);
 782         cred->gc_uid = acred->uid;
 783         /*
 784          * Note: in order to force a call to call_refresh(), we deliberately
 785          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
 786          */
 787         cred->gc_flags = 0;
 788         cred->gc_base.cr_ops = &gss_credops;
 789         cred->gc_service = gss_auth->service;
 790         err = gss_create_upcall(gss_auth, cred);
 791         if (err < 0)
 792                 goto out_err;
 793
 794         return &cred->gc_base;
 795
 796 out_err:
 797         dprintk("RPC:      gss_create_cred failed with error %d\n", err);
 798         if (cred) gss_destroy_cred(&cred->gc_base);
 799         return ERR_PTR(err);
 800 }
 801
 802 static int
 803 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int taskflags)
 804 {
 805         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 806
 807         /* Don't match with creds that have expired. */
 808         if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
 809                 return 0;
 810         return (rc->cr_uid == acred->uid);
 811 }
 812
 813 /*
 814 * Marshal credentials.
 815 * Maybe we should keep a cached credential for performance reasons.
 816 */
 817 static u32 *
 818 gss_marshal(struct rpc_task *task, u32 *p)
 819 {
 820         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 821         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 822                                                  gc_base);
 823         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
 824         u32             *cred_len;
 825         struct rpc_rqst *req = task->tk_rqstp;
 826         u32             maj_stat = 0;
 827         struct xdr_netobj mic;
 828         struct kvec     iov;
 829         struct xdr_buf  verf_buf;
 830
 831         dprintk("RPC: %4u gss_marshal\n", task->tk_pid);
 832
 833         *p++ = htonl(RPC_AUTH_GSS);
 834         cred_len = p++;
 835
 836         spin_lock(&ctx->gc_seq_lock);
 837         req->rq_seqno = ctx->gc_seq++;
 838         spin_unlock(&ctx->gc_seq_lock);
 839
 840         *p++ = htonl((u32) RPC_GSS_VERSION);
 841         *p++ = htonl((u32) ctx->gc_proc);
 842         *p++ = htonl((u32) req->rq_seqno);
 843         *p++ = htonl((u32) gss_cred->gc_service);
 844         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
 845         *cred_len = htonl((p - (cred_len + 1)) << 2);
 846
 847         /* We compute the checksum for the verifier over the xdr-encoded bytes
 848          * starting with the xid and ending at the end of the credential: */
 849         iov.iov_base = req->rq_snd_buf.head[0].iov_base;
 850         if (task->tk_client->cl_xprt->stream)
 851                 /* See clnt.c:call_header() */
 852                 iov.iov_base += 4;
 853         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
 854         xdr_buf_from_iov(&iov, &verf_buf);
 855
 856         /* set verifier flavor*/
 857         *p++ = htonl(RPC_AUTH_GSS);
 858
 859         mic.data = (u8 *)(p + 1);
 860         maj_stat = gss_get_mic(ctx->gc_gss_ctx,
 861                                GSS_C_QOP_DEFAULT,
 862                                &verf_buf, &mic);
 863         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
 864                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 865         } else if (maj_stat != 0) {
 866                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
 867                 goto out_put_ctx;
 868         }
 869         p = xdr_encode_opaque(p, NULL, mic.len);
 870         gss_put_ctx(ctx);
 871         return p;
 872 out_put_ctx:
 873         gss_put_ctx(ctx);
 874         return NULL;
 875 }
 876
 877 /*
 878 * Refresh credentials. XXX - finish
 879 */
 880 static int
 881 gss_refresh(struct rpc_task *task)
 882 {
 883
 884         if (!gss_cred_is_uptodate_ctx(task->tk_msg.rpc_cred))
 885                 return gss_refresh_upcall(task);
 886         return 0;
 887 }
 888
 889 static u32 *
 890 gss_validate(struct rpc_task *task, u32 *p)
 891 {
 892         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 893         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 894                                                 gc_base);
 895         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
 896         u32             seq, qop_state;
 897         struct kvec     iov;
 898         struct xdr_buf  verf_buf;
 899         struct xdr_netobj mic;
 900         u32             flav,len;
 901         u32             maj_stat;
 902
 903         dprintk("RPC: %4u gss_validate\n", task->tk_pid);
 904
 905         flav = ntohl(*p++);
 906         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
 907                 goto out_bad;
 908         if (flav != RPC_AUTH_GSS)
 909                 goto out_bad;
 910         seq = htonl(task->tk_rqstp->rq_seqno);
 911         iov.iov_base = &seq;
 912         iov.iov_len = sizeof(seq);
 913         xdr_buf_from_iov(&iov, &verf_buf);
 914         mic.data = (u8 *)p;
 915         mic.len = len;
 916
 917         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic, &qop_state);
 918         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 919                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 920         if (maj_stat)
 921                 goto out_bad;
 922        switch (gss_cred->gc_service) {
 923        case RPC_GSS_SVC_NONE:
 924                /* verifier data, flavor, length: */
 925                task->tk_auth->au_rslack = XDR_QUADLEN(len) + 2;
 926                break;
 927        case RPC_GSS_SVC_INTEGRITY:
 928                /* verifier data, flavor, length, length, sequence number: */
 929                task->tk_auth->au_rslack = XDR_QUADLEN(len) + 4;
 930                break;
 931        case RPC_GSS_SVC_PRIVACY:
 932                goto out_bad;
 933        }
 934         gss_put_ctx(ctx);
 935         dprintk("RPC: %4u GSS gss_validate: gss_verify_mic succeeded.\n",
 936                         task->tk_pid);
 937         return p + XDR_QUADLEN(len);
 938 out_bad:
 939         gss_put_ctx(ctx);
 940         dprintk("RPC: %4u gss_validate failed.\n", task->tk_pid);
 941         return NULL;
 942 }
 943
 944 static inline int
 945 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 946                 kxdrproc_t encode, struct rpc_rqst *rqstp, u32 *p, void *obj)
 947 {
 948         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
 949         struct xdr_buf  integ_buf;
 950         u32             *integ_len = NULL;
 951         struct xdr_netobj mic;
 952         u32             offset, *q;
 953         struct kvec     *iov;
 954         u32             maj_stat = 0;
 955         int             status = -EIO;
 956
 957         integ_len = p++;
 958         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 959         *p++ = htonl(rqstp->rq_seqno);
 960
 961         status = encode(rqstp, p, obj);
 962         if (status)
 963                 return status;
 964
 965         if (xdr_buf_subsegment(snd_buf, &integ_buf,
 966                                 offset, snd_buf->len - offset))
 967                 return status;
 968         *integ_len = htonl(integ_buf.len);
 969
 970         /* guess whether we're in the head or the tail: */
 971         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
 972                 iov = snd_buf->tail;
 973         else
 974                 iov = snd_buf->head;
 975         p = iov->iov_base + iov->iov_len;
 976         mic.data = (u8 *)(p + 1);
 977
 978         maj_stat = gss_get_mic(ctx->gc_gss_ctx,
 979                         GSS_C_QOP_DEFAULT, &integ_buf, &mic);
 980         status = -EIO; /* XXX? */
 981         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
 982                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
 983         else if (maj_stat)
 984                 return status;
 985         q = xdr_encode_opaque(p, NULL, mic.len);
 986
 987         offset = (u8 *)q - (u8 *)p;
 988         iov->iov_len += offset;
 989         snd_buf->len += offset;
 990         return 0;
 991 }
 992
 993 static int
 994 gss_wrap_req(struct rpc_task *task,
 995              kxdrproc_t encode, void *rqstp, u32 *p, void *obj)
 996 {
 997         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 998         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
 999                         gc_base);
1000         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1001         int             status = -EIO;
1002
1003         dprintk("RPC: %4u gss_wrap_req\n", task->tk_pid);
1004         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1005                 /* The spec seems a little ambiguous here, but I think that not
1006                  * wrapping context destruction requests makes the most sense.
1007                  */
1008                 status = encode(rqstp, p, obj);
1009                 goto out;
1010         }
1011         switch (gss_cred->gc_service) {
1012                 case RPC_GSS_SVC_NONE:
1013                         status = encode(rqstp, p, obj);
1014                         break;
1015                 case RPC_GSS_SVC_INTEGRITY:
1016                         status = gss_wrap_req_integ(cred, ctx, encode,
1017                                                                 rqstp, p, obj);
1018                         break;
1019                 case RPC_GSS_SVC_PRIVACY:
1020                         break;
1021         }
1022 out:
1023         gss_put_ctx(ctx);
1024         dprintk("RPC: %4u gss_wrap_req returning %d\n", task->tk_pid, status);
1025         return status;
1026 }
1027
1028 static inline int
1029 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1030                 struct rpc_rqst *rqstp, u32 **p)
1031 {
1032         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1033         struct xdr_buf integ_buf;
1034         struct xdr_netobj mic;
1035         u32 data_offset, mic_offset;
1036         u32 integ_len;
1037         u32 maj_stat;
1038         int status = -EIO;
1039
1040         integ_len = ntohl(*(*p)++);
1041         if (integ_len & 3)
1042                 return status;
1043         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1044         mic_offset = integ_len + data_offset;
1045         if (mic_offset > rcv_buf->len)
1046                 return status;
1047         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1048                 return status;
1049
1050         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1051                                 mic_offset - data_offset))
1052                 return status;
1053
1054         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1055                 return status;
1056
1057         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf,
1058                         &mic, NULL);
1059         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1060                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
1061         if (maj_stat != GSS_S_COMPLETE)
1062                 return status;
1063         return 0;
1064 }
1065
1066 static int
1067 gss_unwrap_resp(struct rpc_task *task,
1068                 kxdrproc_t decode, void *rqstp, u32 *p, void *obj)
1069 {
1070         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1071         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1072                         gc_base);
1073         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1074         int             status = -EIO;
1075
1076         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1077                 goto out_decode;
1078         switch (gss_cred->gc_service) {
1079                 case RPC_GSS_SVC_NONE:
1080                         break;
1081                 case RPC_GSS_SVC_INTEGRITY:
1082                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1083                         if (status)
1084                                 goto out;
1085                         break;
1086                 case RPC_GSS_SVC_PRIVACY:
1087                         break;
1088         }
1089 out_decode:
1090         status = decode(rqstp, p, obj);
1091 out:
1092         gss_put_ctx(ctx);
1093         dprintk("RPC: %4u gss_unwrap_resp returning %d\n", task->tk_pid,
1094                         status);
1095         return status;
1096 }
1097
1098 static struct rpc_authops authgss_ops = {
1099         .owner          = THIS_MODULE,
1100         .au_flavor      = RPC_AUTH_GSS,
1101 #ifdef RPC_DEBUG
1102         .au_name        = "RPCSEC_GSS",
1103 #endif
1104         .create         = gss_create,
1105         .destroy        = gss_destroy,
1106         .lookup_cred    = gss_lookup_cred,
1107         .crcreate       = gss_create_cred
1108 };
1109
1110 static struct rpc_credops gss_credops = {
1111         .cr_name        = "AUTH_GSS",
1112         .crdestroy      = gss_destroy_cred,
1113         .crmatch        = gss_match,
1114         .crmarshal      = gss_marshal,
1115         .crrefresh      = gss_refresh,
1116         .crvalidate     = gss_validate,
1117         .crwrap_req     = gss_wrap_req,
1118         .crunwrap_resp  = gss_unwrap_resp,
1119 };
1120
1121 static struct rpc_pipe_ops gss_upcall_ops = {
1122         .upcall         = gss_pipe_upcall,
1123         .downcall       = gss_pipe_downcall,
1124         .destroy_msg    = gss_pipe_destroy_msg,
1125         .release_pipe   = gss_pipe_release,
1126 };
1127
1128 /*
1129  * Initialize RPCSEC_GSS module
1130  */
1131 static int __init init_rpcsec_gss(void)
1132 {
1133         int err = 0;
1134
1135         err = rpcauth_register(&authgss_ops);
1136         if (err)
1137                 goto out;
1138         err = gss_svc_init();
1139         if (err)
1140                 goto out_unregister;
1141         return 0;
1142 out_unregister:
1143         rpcauth_unregister(&authgss_ops);
1144 out:
1145         return err;
1146 }
1147
1148 static void __exit exit_rpcsec_gss(void)
1149 {
1150         gss_svc_shutdown();
1151         rpcauth_unregister(&authgss_ops);
1152 }
1153
1154 MODULE_LICENSE("GPL");
1155 module_init(init_rpcsec_gss)
1156 module_exit(exit_rpcsec_gss)