1 /* 2 * linux/net/sunrpc/auth_gss/auth_gss.c 3 * 4 * RPCSEC_GSS client authentication. 5 * 6 * Copyright (c) 2000 The Regents of the University of Michigan. 7 * All rights reserved. 8 * 9 * Dug Song <dugsong@monkey.org> 10 * Andy Adamson <andros@umich.edu> 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its 22 * contributors may be used to endorse or promote products derived 23 * from this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 26 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 27 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 28 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 32 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 33 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 34 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 35 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 39 #include <linux/module.h> 40 #include <linux/init.h> 41 #include <linux/types.h> 42 #include <linux/slab.h> 43 #include <linux/sched.h> 44 #include <linux/pagemap.h> 45 #include <linux/sunrpc/clnt.h> 46 #include <linux/sunrpc/auth.h> 47 #include <linux/sunrpc/auth_gss.h> 48 #include <linux/sunrpc/svcauth_gss.h> 49 #include <linux/sunrpc/gss_err.h> 50 #include <linux/workqueue.h> 51 #include <linux/sunrpc/rpc_pipe_fs.h> 52 #include <linux/sunrpc/gss_api.h> 53 #include <asm/uaccess.h> 54 55 static const struct rpc_authops authgss_ops; 56 57 static const struct rpc_credops gss_credops; 58 static const struct rpc_credops gss_nullops; 59 60 #define GSS_RETRY_EXPIRED 5 61 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED; 62 63 #ifdef RPC_DEBUG 64 # define RPCDBG_FACILITY RPCDBG_AUTH 65 #endif 66 67 #define GSS_CRED_SLACK (RPC_MAX_AUTH_SIZE * 2) 68 /* length of a krb5 verifier (48), plus data added before arguments when 69 * using integrity (two 4-byte integers): */ 70 #define GSS_VERF_SLACK 100 71 72 struct gss_auth { 73 struct kref kref; 74 struct rpc_auth rpc_auth; 75 struct gss_api_mech *mech; 76 enum rpc_gss_svc service; 77 struct rpc_clnt *client; 78 /* 79 * There are two upcall pipes; dentry[1], named "gssd", is used 80 * for the new text-based upcall; dentry[0] is named after the 81 * mechanism (for example, "krb5") and exists for 82 * backwards-compatibility with older gssd's. 83 */ 84 struct dentry *dentry[2]; 85 }; 86 87 /* pipe_version >= 0 if and only if someone has a pipe open. */ 88 static int pipe_version = -1; 89 static atomic_t pipe_users = ATOMIC_INIT(0); 90 static DEFINE_SPINLOCK(pipe_version_lock); 91 static struct rpc_wait_queue pipe_version_rpc_waitqueue; 92 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue); 93 94 static void gss_free_ctx(struct gss_cl_ctx *); 95 static const struct rpc_pipe_ops gss_upcall_ops_v0; 96 static const struct rpc_pipe_ops gss_upcall_ops_v1; 97 98 static inline struct gss_cl_ctx * 99 gss_get_ctx(struct gss_cl_ctx *ctx) 100 { 101 atomic_inc(&ctx->count); 102 return ctx; 103 } 104 105 static inline void 106 gss_put_ctx(struct gss_cl_ctx *ctx) 107 { 108 if (atomic_dec_and_test(&ctx->count)) 109 gss_free_ctx(ctx); 110 } 111 112 /* gss_cred_set_ctx: 113 * called by gss_upcall_callback and gss_create_upcall in order 114 * to set the gss context. The actual exchange of an old context 115 * and a new one is protected by the inode->i_lock. 116 */ 117 static void 118 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx) 119 { 120 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 121 122 if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)) 123 return; 124 gss_get_ctx(ctx); 125 rcu_assign_pointer(gss_cred->gc_ctx, ctx); 126 set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 127 smp_mb__before_clear_bit(); 128 clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags); 129 } 130 131 static const void * 132 simple_get_bytes(const void *p, const void *end, void *res, size_t len) 133 { 134 const void *q = (const void *)((const char *)p + len); 135 if (unlikely(q > end || q < p)) 136 return ERR_PTR(-EFAULT); 137 memcpy(res, p, len); 138 return q; 139 } 140 141 static inline const void * 142 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest) 143 { 144 const void *q; 145 unsigned int len; 146 147 p = simple_get_bytes(p, end, &len, sizeof(len)); 148 if (IS_ERR(p)) 149 return p; 150 q = (const void *)((const char *)p + len); 151 if (unlikely(q > end || q < p)) 152 return ERR_PTR(-EFAULT); 153 dest->data = kmemdup(p, len, GFP_NOFS); 154 if (unlikely(dest->data == NULL)) 155 return ERR_PTR(-ENOMEM); 156 dest->len = len; 157 return q; 158 } 159 160 static struct gss_cl_ctx * 161 gss_cred_get_ctx(struct rpc_cred *cred) 162 { 163 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 164 struct gss_cl_ctx *ctx = NULL; 165 166 rcu_read_lock(); 167 if (gss_cred->gc_ctx) 168 ctx = gss_get_ctx(gss_cred->gc_ctx); 169 rcu_read_unlock(); 170 return ctx; 171 } 172 173 static struct gss_cl_ctx * 174 gss_alloc_context(void) 175 { 176 struct gss_cl_ctx *ctx; 177 178 ctx = kzalloc(sizeof(*ctx), GFP_NOFS); 179 if (ctx != NULL) { 180 ctx->gc_proc = RPC_GSS_PROC_DATA; 181 ctx->gc_seq = 1; /* NetApp 6.4R1 doesn't accept seq. no. 0 */ 182 spin_lock_init(&ctx->gc_seq_lock); 183 atomic_set(&ctx->count,1); 184 } 185 return ctx; 186 } 187 188 #define GSSD_MIN_TIMEOUT (60 * 60) 189 static const void * 190 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm) 191 { 192 const void *q; 193 unsigned int seclen; 194 unsigned int timeout; 195 u32 window_size; 196 int ret; 197 198 /* First unsigned int gives the lifetime (in seconds) of the cred */ 199 p = simple_get_bytes(p, end, &timeout, sizeof(timeout)); 200 if (IS_ERR(p)) 201 goto err; 202 if (timeout == 0) 203 timeout = GSSD_MIN_TIMEOUT; 204 ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4; 205 /* Sequence number window. Determines the maximum number of simultaneous requests */ 206 p = simple_get_bytes(p, end, &window_size, sizeof(window_size)); 207 if (IS_ERR(p)) 208 goto err; 209 ctx->gc_win = window_size; 210 /* gssd signals an error by passing ctx->gc_win = 0: */ 211 if (ctx->gc_win == 0) { 212 /* 213 * in which case, p points to an error code. Anything other 214 * than -EKEYEXPIRED gets converted to -EACCES. 215 */ 216 p = simple_get_bytes(p, end, &ret, sizeof(ret)); 217 if (!IS_ERR(p)) 218 p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) : 219 ERR_PTR(-EACCES); 220 goto err; 221 } 222 /* copy the opaque wire context */ 223 p = simple_get_netobj(p, end, &ctx->gc_wire_ctx); 224 if (IS_ERR(p)) 225 goto err; 226 /* import the opaque security context */ 227 p = simple_get_bytes(p, end, &seclen, sizeof(seclen)); 228 if (IS_ERR(p)) 229 goto err; 230 q = (const void *)((const char *)p + seclen); 231 if (unlikely(q > end || q < p)) { 232 p = ERR_PTR(-EFAULT); 233 goto err; 234 } 235 ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, GFP_NOFS); 236 if (ret < 0) { 237 p = ERR_PTR(ret); 238 goto err; 239 } 240 return q; 241 err: 242 dprintk("RPC: gss_fill_context returning %ld\n", -PTR_ERR(p)); 243 return p; 244 } 245 246 #define UPCALL_BUF_LEN 128 247 248 struct gss_upcall_msg { 249 atomic_t count; 250 uid_t uid; 251 struct rpc_pipe_msg msg; 252 struct list_head list; 253 struct gss_auth *auth; 254 struct rpc_inode *inode; 255 struct rpc_wait_queue rpc_waitqueue; 256 wait_queue_head_t waitqueue; 257 struct gss_cl_ctx *ctx; 258 char databuf[UPCALL_BUF_LEN]; 259 }; 260 261 static int get_pipe_version(void) 262 { 263 int ret; 264 265 spin_lock(&pipe_version_lock); 266 if (pipe_version >= 0) { 267 atomic_inc(&pipe_users); 268 ret = pipe_version; 269 } else 270 ret = -EAGAIN; 271 spin_unlock(&pipe_version_lock); 272 return ret; 273 } 274 275 static void put_pipe_version(void) 276 { 277 if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) { 278 pipe_version = -1; 279 spin_unlock(&pipe_version_lock); 280 } 281 } 282 283 static void 284 gss_release_msg(struct gss_upcall_msg *gss_msg) 285 { 286 if (!atomic_dec_and_test(&gss_msg->count)) 287 return; 288 put_pipe_version(); 289 BUG_ON(!list_empty(&gss_msg->list)); 290 if (gss_msg->ctx != NULL) 291 gss_put_ctx(gss_msg->ctx); 292 rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue); 293 kfree(gss_msg); 294 } 295 296 static struct gss_upcall_msg * 297 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid) 298 { 299 struct gss_upcall_msg *pos; 300 list_for_each_entry(pos, &rpci->in_downcall, list) { 301 if (pos->uid != uid) 302 continue; 303 atomic_inc(&pos->count); 304 dprintk("RPC: gss_find_upcall found msg %p\n", pos); 305 return pos; 306 } 307 dprintk("RPC: gss_find_upcall found nothing\n"); 308 return NULL; 309 } 310 311 /* Try to add an upcall to the pipefs queue. 312 * If an upcall owned by our uid already exists, then we return a reference 313 * to that upcall instead of adding the new upcall. 314 */ 315 static inline struct gss_upcall_msg * 316 gss_add_msg(struct gss_upcall_msg *gss_msg) 317 { 318 struct rpc_inode *rpci = gss_msg->inode; 319 struct inode *inode = &rpci->vfs_inode; 320 struct gss_upcall_msg *old; 321 322 spin_lock(&inode->i_lock); 323 old = __gss_find_upcall(rpci, gss_msg->uid); 324 if (old == NULL) { 325 atomic_inc(&gss_msg->count); 326 list_add(&gss_msg->list, &rpci->in_downcall); 327 } else 328 gss_msg = old; 329 spin_unlock(&inode->i_lock); 330 return gss_msg; 331 } 332 333 static void 334 __gss_unhash_msg(struct gss_upcall_msg *gss_msg) 335 { 336 list_del_init(&gss_msg->list); 337 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno); 338 wake_up_all(&gss_msg->waitqueue); 339 atomic_dec(&gss_msg->count); 340 } 341 342 static void 343 gss_unhash_msg(struct gss_upcall_msg *gss_msg) 344 { 345 struct inode *inode = &gss_msg->inode->vfs_inode; 346 347 if (list_empty(&gss_msg->list)) 348 return; 349 spin_lock(&inode->i_lock); 350 if (!list_empty(&gss_msg->list)) 351 __gss_unhash_msg(gss_msg); 352 spin_unlock(&inode->i_lock); 353 } 354 355 static void 356 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg) 357 { 358 switch (gss_msg->msg.errno) { 359 case 0: 360 if (gss_msg->ctx == NULL) 361 break; 362 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags); 363 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx); 364 break; 365 case -EKEYEXPIRED: 366 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags); 367 } 368 gss_cred->gc_upcall_timestamp = jiffies; 369 gss_cred->gc_upcall = NULL; 370 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno); 371 } 372 373 static void 374 gss_upcall_callback(struct rpc_task *task) 375 { 376 struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred, 377 struct gss_cred, gc_base); 378 struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall; 379 struct inode *inode = &gss_msg->inode->vfs_inode; 380 381 spin_lock(&inode->i_lock); 382 gss_handle_downcall_result(gss_cred, gss_msg); 383 spin_unlock(&inode->i_lock); 384 task->tk_status = gss_msg->msg.errno; 385 gss_release_msg(gss_msg); 386 } 387 388 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg) 389 { 390 gss_msg->msg.data = &gss_msg->uid; 391 gss_msg->msg.len = sizeof(gss_msg->uid); 392 } 393 394 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg, 395 struct rpc_clnt *clnt, int machine_cred) 396 { 397 struct gss_api_mech *mech = gss_msg->auth->mech; 398 char *p = gss_msg->databuf; 399 int len = 0; 400 401 gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ", 402 mech->gm_name, 403 gss_msg->uid); 404 p += gss_msg->msg.len; 405 if (clnt->cl_principal) { 406 len = sprintf(p, "target=%s ", clnt->cl_principal); 407 p += len; 408 gss_msg->msg.len += len; 409 } 410 if (machine_cred) { 411 len = sprintf(p, "service=* "); 412 p += len; 413 gss_msg->msg.len += len; 414 } else if (!strcmp(clnt->cl_program->name, "nfs4_cb")) { 415 len = sprintf(p, "service=nfs "); 416 p += len; 417 gss_msg->msg.len += len; 418 } 419 if (mech->gm_upcall_enctypes) { 420 len = sprintf(p, "enctypes=%s ", mech->gm_upcall_enctypes); 421 p += len; 422 gss_msg->msg.len += len; 423 } 424 len = sprintf(p, "\n"); 425 gss_msg->msg.len += len; 426 427 gss_msg->msg.data = gss_msg->databuf; 428 BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN); 429 } 430 431 static void gss_encode_msg(struct gss_upcall_msg *gss_msg, 432 struct rpc_clnt *clnt, int machine_cred) 433 { 434 if (pipe_version == 0) 435 gss_encode_v0_msg(gss_msg); 436 else /* pipe_version == 1 */ 437 gss_encode_v1_msg(gss_msg, clnt, machine_cred); 438 } 439 440 static inline struct gss_upcall_msg * 441 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid, struct rpc_clnt *clnt, 442 int machine_cred) 443 { 444 struct gss_upcall_msg *gss_msg; 445 int vers; 446 447 gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS); 448 if (gss_msg == NULL) 449 return ERR_PTR(-ENOMEM); 450 vers = get_pipe_version(); 451 if (vers < 0) { 452 kfree(gss_msg); 453 return ERR_PTR(vers); 454 } 455 gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode); 456 INIT_LIST_HEAD(&gss_msg->list); 457 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq"); 458 init_waitqueue_head(&gss_msg->waitqueue); 459 atomic_set(&gss_msg->count, 1); 460 gss_msg->uid = uid; 461 gss_msg->auth = gss_auth; 462 gss_encode_msg(gss_msg, clnt, machine_cred); 463 return gss_msg; 464 } 465 466 static struct gss_upcall_msg * 467 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred) 468 { 469 struct gss_cred *gss_cred = container_of(cred, 470 struct gss_cred, gc_base); 471 struct gss_upcall_msg *gss_new, *gss_msg; 472 uid_t uid = cred->cr_uid; 473 474 gss_new = gss_alloc_msg(gss_auth, uid, clnt, gss_cred->gc_machine_cred); 475 if (IS_ERR(gss_new)) 476 return gss_new; 477 gss_msg = gss_add_msg(gss_new); 478 if (gss_msg == gss_new) { 479 struct inode *inode = &gss_new->inode->vfs_inode; 480 int res = rpc_queue_upcall(inode, &gss_new->msg); 481 if (res) { 482 gss_unhash_msg(gss_new); 483 gss_msg = ERR_PTR(res); 484 } 485 } else 486 gss_release_msg(gss_new); 487 return gss_msg; 488 } 489 490 static void warn_gssd(void) 491 { 492 static unsigned long ratelimit; 493 unsigned long now = jiffies; 494 495 if (time_after(now, ratelimit)) { 496 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n" 497 "Please check user daemon is running.\n"); 498 ratelimit = now + 15*HZ; 499 } 500 } 501 502 static inline int 503 gss_refresh_upcall(struct rpc_task *task) 504 { 505 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 506 struct gss_auth *gss_auth = container_of(cred->cr_auth, 507 struct gss_auth, rpc_auth); 508 struct gss_cred *gss_cred = container_of(cred, 509 struct gss_cred, gc_base); 510 struct gss_upcall_msg *gss_msg; 511 struct inode *inode; 512 int err = 0; 513 514 dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid, 515 cred->cr_uid); 516 gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred); 517 if (PTR_ERR(gss_msg) == -EAGAIN) { 518 /* XXX: warning on the first, under the assumption we 519 * shouldn't normally hit this case on a refresh. */ 520 warn_gssd(); 521 task->tk_timeout = 15*HZ; 522 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL); 523 return -EAGAIN; 524 } 525 if (IS_ERR(gss_msg)) { 526 err = PTR_ERR(gss_msg); 527 goto out; 528 } 529 inode = &gss_msg->inode->vfs_inode; 530 spin_lock(&inode->i_lock); 531 if (gss_cred->gc_upcall != NULL) 532 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL); 533 else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) { 534 task->tk_timeout = 0; 535 gss_cred->gc_upcall = gss_msg; 536 /* gss_upcall_callback will release the reference to gss_upcall_msg */ 537 atomic_inc(&gss_msg->count); 538 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback); 539 } else { 540 gss_handle_downcall_result(gss_cred, gss_msg); 541 err = gss_msg->msg.errno; 542 } 543 spin_unlock(&inode->i_lock); 544 gss_release_msg(gss_msg); 545 out: 546 dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n", 547 task->tk_pid, cred->cr_uid, err); 548 return err; 549 } 550 551 static inline int 552 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred) 553 { 554 struct inode *inode; 555 struct rpc_cred *cred = &gss_cred->gc_base; 556 struct gss_upcall_msg *gss_msg; 557 DEFINE_WAIT(wait); 558 int err = 0; 559 560 dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid); 561 retry: 562 gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred); 563 if (PTR_ERR(gss_msg) == -EAGAIN) { 564 err = wait_event_interruptible_timeout(pipe_version_waitqueue, 565 pipe_version >= 0, 15*HZ); 566 if (pipe_version < 0) { 567 warn_gssd(); 568 err = -EACCES; 569 } 570 if (err) 571 goto out; 572 goto retry; 573 } 574 if (IS_ERR(gss_msg)) { 575 err = PTR_ERR(gss_msg); 576 goto out; 577 } 578 inode = &gss_msg->inode->vfs_inode; 579 for (;;) { 580 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE); 581 spin_lock(&inode->i_lock); 582 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) { 583 break; 584 } 585 spin_unlock(&inode->i_lock); 586 if (fatal_signal_pending(current)) { 587 err = -ERESTARTSYS; 588 goto out_intr; 589 } 590 schedule(); 591 } 592 if (gss_msg->ctx) 593 gss_cred_set_ctx(cred, gss_msg->ctx); 594 else 595 err = gss_msg->msg.errno; 596 spin_unlock(&inode->i_lock); 597 out_intr: 598 finish_wait(&gss_msg->waitqueue, &wait); 599 gss_release_msg(gss_msg); 600 out: 601 dprintk("RPC: gss_create_upcall for uid %u result %d\n", 602 cred->cr_uid, err); 603 return err; 604 } 605 606 static ssize_t 607 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg, 608 char __user *dst, size_t buflen) 609 { 610 char *data = (char *)msg->data + msg->copied; 611 size_t mlen = min(msg->len, buflen); 612 unsigned long left; 613 614 left = copy_to_user(dst, data, mlen); 615 if (left == mlen) { 616 msg->errno = -EFAULT; 617 return -EFAULT; 618 } 619 620 mlen -= left; 621 msg->copied += mlen; 622 msg->errno = 0; 623 return mlen; 624 } 625 626 #define MSG_BUF_MAXSIZE 1024 627 628 static ssize_t 629 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) 630 { 631 const void *p, *end; 632 void *buf; 633 struct gss_upcall_msg *gss_msg; 634 struct inode *inode = filp->f_path.dentry->d_inode; 635 struct gss_cl_ctx *ctx; 636 uid_t uid; 637 ssize_t err = -EFBIG; 638 639 if (mlen > MSG_BUF_MAXSIZE) 640 goto out; 641 err = -ENOMEM; 642 buf = kmalloc(mlen, GFP_NOFS); 643 if (!buf) 644 goto out; 645 646 err = -EFAULT; 647 if (copy_from_user(buf, src, mlen)) 648 goto err; 649 650 end = (const void *)((char *)buf + mlen); 651 p = simple_get_bytes(buf, end, &uid, sizeof(uid)); 652 if (IS_ERR(p)) { 653 err = PTR_ERR(p); 654 goto err; 655 } 656 657 err = -ENOMEM; 658 ctx = gss_alloc_context(); 659 if (ctx == NULL) 660 goto err; 661 662 err = -ENOENT; 663 /* Find a matching upcall */ 664 spin_lock(&inode->i_lock); 665 gss_msg = __gss_find_upcall(RPC_I(inode), uid); 666 if (gss_msg == NULL) { 667 spin_unlock(&inode->i_lock); 668 goto err_put_ctx; 669 } 670 list_del_init(&gss_msg->list); 671 spin_unlock(&inode->i_lock); 672 673 p = gss_fill_context(p, end, ctx, gss_msg->auth->mech); 674 if (IS_ERR(p)) { 675 err = PTR_ERR(p); 676 switch (err) { 677 case -EACCES: 678 case -EKEYEXPIRED: 679 gss_msg->msg.errno = err; 680 err = mlen; 681 break; 682 case -EFAULT: 683 case -ENOMEM: 684 case -EINVAL: 685 case -ENOSYS: 686 gss_msg->msg.errno = -EAGAIN; 687 break; 688 default: 689 printk(KERN_CRIT "%s: bad return from " 690 "gss_fill_context: %zd\n", __func__, err); 691 BUG(); 692 } 693 goto err_release_msg; 694 } 695 gss_msg->ctx = gss_get_ctx(ctx); 696 err = mlen; 697 698 err_release_msg: 699 spin_lock(&inode->i_lock); 700 __gss_unhash_msg(gss_msg); 701 spin_unlock(&inode->i_lock); 702 gss_release_msg(gss_msg); 703 err_put_ctx: 704 gss_put_ctx(ctx); 705 err: 706 kfree(buf); 707 out: 708 dprintk("RPC: gss_pipe_downcall returning %Zd\n", err); 709 return err; 710 } 711 712 static int gss_pipe_open(struct inode *inode, int new_version) 713 { 714 int ret = 0; 715 716 spin_lock(&pipe_version_lock); 717 if (pipe_version < 0) { 718 /* First open of any gss pipe determines the version: */ 719 pipe_version = new_version; 720 rpc_wake_up(&pipe_version_rpc_waitqueue); 721 wake_up(&pipe_version_waitqueue); 722 } else if (pipe_version != new_version) { 723 /* Trying to open a pipe of a different version */ 724 ret = -EBUSY; 725 goto out; 726 } 727 atomic_inc(&pipe_users); 728 out: 729 spin_unlock(&pipe_version_lock); 730 return ret; 731 732 } 733 734 static int gss_pipe_open_v0(struct inode *inode) 735 { 736 return gss_pipe_open(inode, 0); 737 } 738 739 static int gss_pipe_open_v1(struct inode *inode) 740 { 741 return gss_pipe_open(inode, 1); 742 } 743 744 static void 745 gss_pipe_release(struct inode *inode) 746 { 747 struct rpc_inode *rpci = RPC_I(inode); 748 struct gss_upcall_msg *gss_msg; 749 750 restart: 751 spin_lock(&inode->i_lock); 752 list_for_each_entry(gss_msg, &rpci->in_downcall, list) { 753 754 if (!list_empty(&gss_msg->msg.list)) 755 continue; 756 gss_msg->msg.errno = -EPIPE; 757 atomic_inc(&gss_msg->count); 758 __gss_unhash_msg(gss_msg); 759 spin_unlock(&inode->i_lock); 760 gss_release_msg(gss_msg); 761 goto restart; 762 } 763 spin_unlock(&inode->i_lock); 764 765 put_pipe_version(); 766 } 767 768 static void 769 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg) 770 { 771 struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg); 772 773 if (msg->errno < 0) { 774 dprintk("RPC: gss_pipe_destroy_msg releasing msg %p\n", 775 gss_msg); 776 atomic_inc(&gss_msg->count); 777 gss_unhash_msg(gss_msg); 778 if (msg->errno == -ETIMEDOUT) 779 warn_gssd(); 780 gss_release_msg(gss_msg); 781 } 782 } 783 784 /* 785 * NOTE: we have the opportunity to use different 786 * parameters based on the input flavor (which must be a pseudoflavor) 787 */ 788 static struct rpc_auth * 789 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor) 790 { 791 struct gss_auth *gss_auth; 792 struct rpc_auth * auth; 793 int err = -ENOMEM; /* XXX? */ 794 795 dprintk("RPC: creating GSS authenticator for client %p\n", clnt); 796 797 if (!try_module_get(THIS_MODULE)) 798 return ERR_PTR(err); 799 if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL))) 800 goto out_dec; 801 gss_auth->client = clnt; 802 err = -EINVAL; 803 gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor); 804 if (!gss_auth->mech) { 805 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n", 806 __func__, flavor); 807 goto err_free; 808 } 809 gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor); 810 if (gss_auth->service == 0) 811 goto err_put_mech; 812 auth = &gss_auth->rpc_auth; 813 auth->au_cslack = GSS_CRED_SLACK >> 2; 814 auth->au_rslack = GSS_VERF_SLACK >> 2; 815 auth->au_ops = &authgss_ops; 816 auth->au_flavor = flavor; 817 atomic_set(&auth->au_count, 1); 818 kref_init(&gss_auth->kref); 819 820 /* 821 * Note: if we created the old pipe first, then someone who 822 * examined the directory at the right moment might conclude 823 * that we supported only the old pipe. So we instead create 824 * the new pipe first. 825 */ 826 gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry, 827 "gssd", 828 clnt, &gss_upcall_ops_v1, 829 RPC_PIPE_WAIT_FOR_OPEN); 830 if (IS_ERR(gss_auth->dentry[1])) { 831 err = PTR_ERR(gss_auth->dentry[1]); 832 goto err_put_mech; 833 } 834 835 gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry, 836 gss_auth->mech->gm_name, 837 clnt, &gss_upcall_ops_v0, 838 RPC_PIPE_WAIT_FOR_OPEN); 839 if (IS_ERR(gss_auth->dentry[0])) { 840 err = PTR_ERR(gss_auth->dentry[0]); 841 goto err_unlink_pipe_1; 842 } 843 err = rpcauth_init_credcache(auth); 844 if (err) 845 goto err_unlink_pipe_0; 846 847 return auth; 848 err_unlink_pipe_0: 849 rpc_unlink(gss_auth->dentry[0]); 850 err_unlink_pipe_1: 851 rpc_unlink(gss_auth->dentry[1]); 852 err_put_mech: 853 gss_mech_put(gss_auth->mech); 854 err_free: 855 kfree(gss_auth); 856 out_dec: 857 module_put(THIS_MODULE); 858 return ERR_PTR(err); 859 } 860 861 static void 862 gss_free(struct gss_auth *gss_auth) 863 { 864 rpc_unlink(gss_auth->dentry[1]); 865 rpc_unlink(gss_auth->dentry[0]); 866 gss_mech_put(gss_auth->mech); 867 868 kfree(gss_auth); 869 module_put(THIS_MODULE); 870 } 871 872 static void 873 gss_free_callback(struct kref *kref) 874 { 875 struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref); 876 877 gss_free(gss_auth); 878 } 879 880 static void 881 gss_destroy(struct rpc_auth *auth) 882 { 883 struct gss_auth *gss_auth; 884 885 dprintk("RPC: destroying GSS authenticator %p flavor %d\n", 886 auth, auth->au_flavor); 887 888 rpcauth_destroy_credcache(auth); 889 890 gss_auth = container_of(auth, struct gss_auth, rpc_auth); 891 kref_put(&gss_auth->kref, gss_free_callback); 892 } 893 894 /* 895 * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call 896 * to the server with the GSS control procedure field set to 897 * RPC_GSS_PROC_DESTROY. This should normally cause the server to release 898 * all RPCSEC_GSS state associated with that context. 899 */ 900 static int 901 gss_destroying_context(struct rpc_cred *cred) 902 { 903 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 904 struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth); 905 struct rpc_task *task; 906 907 if (gss_cred->gc_ctx == NULL || 908 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0) 909 return 0; 910 911 gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY; 912 cred->cr_ops = &gss_nullops; 913 914 /* Take a reference to ensure the cred will be destroyed either 915 * by the RPC call or by the put_rpccred() below */ 916 get_rpccred(cred); 917 918 task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT); 919 if (!IS_ERR(task)) 920 rpc_put_task(task); 921 922 put_rpccred(cred); 923 return 1; 924 } 925 926 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure 927 * to create a new cred or context, so they check that things have been 928 * allocated before freeing them. */ 929 static void 930 gss_do_free_ctx(struct gss_cl_ctx *ctx) 931 { 932 dprintk("RPC: gss_free_ctx\n"); 933 934 gss_delete_sec_context(&ctx->gc_gss_ctx); 935 kfree(ctx->gc_wire_ctx.data); 936 kfree(ctx); 937 } 938 939 static void 940 gss_free_ctx_callback(struct rcu_head *head) 941 { 942 struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu); 943 gss_do_free_ctx(ctx); 944 } 945 946 static void 947 gss_free_ctx(struct gss_cl_ctx *ctx) 948 { 949 call_rcu(&ctx->gc_rcu, gss_free_ctx_callback); 950 } 951 952 static void 953 gss_free_cred(struct gss_cred *gss_cred) 954 { 955 dprintk("RPC: gss_free_cred %p\n", gss_cred); 956 kfree(gss_cred); 957 } 958 959 static void 960 gss_free_cred_callback(struct rcu_head *head) 961 { 962 struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu); 963 gss_free_cred(gss_cred); 964 } 965 966 static void 967 gss_destroy_nullcred(struct rpc_cred *cred) 968 { 969 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 970 struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth); 971 struct gss_cl_ctx *ctx = gss_cred->gc_ctx; 972 973 rcu_assign_pointer(gss_cred->gc_ctx, NULL); 974 call_rcu(&cred->cr_rcu, gss_free_cred_callback); 975 if (ctx) 976 gss_put_ctx(ctx); 977 kref_put(&gss_auth->kref, gss_free_callback); 978 } 979 980 static void 981 gss_destroy_cred(struct rpc_cred *cred) 982 { 983 984 if (gss_destroying_context(cred)) 985 return; 986 gss_destroy_nullcred(cred); 987 } 988 989 /* 990 * Lookup RPCSEC_GSS cred for the current process 991 */ 992 static struct rpc_cred * 993 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 994 { 995 return rpcauth_lookup_credcache(auth, acred, flags); 996 } 997 998 static struct rpc_cred * 999 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 1000 { 1001 struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); 1002 struct gss_cred *cred = NULL; 1003 int err = -ENOMEM; 1004 1005 dprintk("RPC: gss_create_cred for uid %d, flavor %d\n", 1006 acred->uid, auth->au_flavor); 1007 1008 if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS))) 1009 goto out_err; 1010 1011 rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops); 1012 /* 1013 * Note: in order to force a call to call_refresh(), we deliberately 1014 * fail to flag the credential as RPCAUTH_CRED_UPTODATE. 1015 */ 1016 cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW; 1017 cred->gc_service = gss_auth->service; 1018 cred->gc_machine_cred = acred->machine_cred; 1019 kref_get(&gss_auth->kref); 1020 return &cred->gc_base; 1021 1022 out_err: 1023 dprintk("RPC: gss_create_cred failed with error %d\n", err); 1024 return ERR_PTR(err); 1025 } 1026 1027 static int 1028 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred) 1029 { 1030 struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); 1031 struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base); 1032 int err; 1033 1034 do { 1035 err = gss_create_upcall(gss_auth, gss_cred); 1036 } while (err == -EAGAIN); 1037 return err; 1038 } 1039 1040 static int 1041 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags) 1042 { 1043 struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base); 1044 1045 if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags)) 1046 goto out; 1047 /* Don't match with creds that have expired. */ 1048 if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry)) 1049 return 0; 1050 if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags)) 1051 return 0; 1052 out: 1053 if (acred->machine_cred != gss_cred->gc_machine_cred) 1054 return 0; 1055 return rc->cr_uid == acred->uid; 1056 } 1057 1058 /* 1059 * Marshal credentials. 1060 * Maybe we should keep a cached credential for performance reasons. 1061 */ 1062 static __be32 * 1063 gss_marshal(struct rpc_task *task, __be32 *p) 1064 { 1065 struct rpc_rqst *req = task->tk_rqstp; 1066 struct rpc_cred *cred = req->rq_cred; 1067 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 1068 gc_base); 1069 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1070 __be32 *cred_len; 1071 u32 maj_stat = 0; 1072 struct xdr_netobj mic; 1073 struct kvec iov; 1074 struct xdr_buf verf_buf; 1075 1076 dprintk("RPC: %5u gss_marshal\n", task->tk_pid); 1077 1078 *p++ = htonl(RPC_AUTH_GSS); 1079 cred_len = p++; 1080 1081 spin_lock(&ctx->gc_seq_lock); 1082 req->rq_seqno = ctx->gc_seq++; 1083 spin_unlock(&ctx->gc_seq_lock); 1084 1085 *p++ = htonl((u32) RPC_GSS_VERSION); 1086 *p++ = htonl((u32) ctx->gc_proc); 1087 *p++ = htonl((u32) req->rq_seqno); 1088 *p++ = htonl((u32) gss_cred->gc_service); 1089 p = xdr_encode_netobj(p, &ctx->gc_wire_ctx); 1090 *cred_len = htonl((p - (cred_len + 1)) << 2); 1091 1092 /* We compute the checksum for the verifier over the xdr-encoded bytes 1093 * starting with the xid and ending at the end of the credential: */ 1094 iov.iov_base = xprt_skip_transport_header(task->tk_xprt, 1095 req->rq_snd_buf.head[0].iov_base); 1096 iov.iov_len = (u8 *)p - (u8 *)iov.iov_base; 1097 xdr_buf_from_iov(&iov, &verf_buf); 1098 1099 /* set verifier flavor*/ 1100 *p++ = htonl(RPC_AUTH_GSS); 1101 1102 mic.data = (u8 *)(p + 1); 1103 maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic); 1104 if (maj_stat == GSS_S_CONTEXT_EXPIRED) { 1105 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1106 } else if (maj_stat != 0) { 1107 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat); 1108 goto out_put_ctx; 1109 } 1110 p = xdr_encode_opaque(p, NULL, mic.len); 1111 gss_put_ctx(ctx); 1112 return p; 1113 out_put_ctx: 1114 gss_put_ctx(ctx); 1115 return NULL; 1116 } 1117 1118 static int gss_renew_cred(struct rpc_task *task) 1119 { 1120 struct rpc_cred *oldcred = task->tk_rqstp->rq_cred; 1121 struct gss_cred *gss_cred = container_of(oldcred, 1122 struct gss_cred, 1123 gc_base); 1124 struct rpc_auth *auth = oldcred->cr_auth; 1125 struct auth_cred acred = { 1126 .uid = oldcred->cr_uid, 1127 .machine_cred = gss_cred->gc_machine_cred, 1128 }; 1129 struct rpc_cred *new; 1130 1131 new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW); 1132 if (IS_ERR(new)) 1133 return PTR_ERR(new); 1134 task->tk_rqstp->rq_cred = new; 1135 put_rpccred(oldcred); 1136 return 0; 1137 } 1138 1139 static int gss_cred_is_negative_entry(struct rpc_cred *cred) 1140 { 1141 if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) { 1142 unsigned long now = jiffies; 1143 unsigned long begin, expire; 1144 struct gss_cred *gss_cred; 1145 1146 gss_cred = container_of(cred, struct gss_cred, gc_base); 1147 begin = gss_cred->gc_upcall_timestamp; 1148 expire = begin + gss_expired_cred_retry_delay * HZ; 1149 1150 if (time_in_range_open(now, begin, expire)) 1151 return 1; 1152 } 1153 return 0; 1154 } 1155 1156 /* 1157 * Refresh credentials. XXX - finish 1158 */ 1159 static int 1160 gss_refresh(struct rpc_task *task) 1161 { 1162 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 1163 int ret = 0; 1164 1165 if (gss_cred_is_negative_entry(cred)) 1166 return -EKEYEXPIRED; 1167 1168 if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) && 1169 !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) { 1170 ret = gss_renew_cred(task); 1171 if (ret < 0) 1172 goto out; 1173 cred = task->tk_rqstp->rq_cred; 1174 } 1175 1176 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)) 1177 ret = gss_refresh_upcall(task); 1178 out: 1179 return ret; 1180 } 1181 1182 /* Dummy refresh routine: used only when destroying the context */ 1183 static int 1184 gss_refresh_null(struct rpc_task *task) 1185 { 1186 return -EACCES; 1187 } 1188 1189 static __be32 * 1190 gss_validate(struct rpc_task *task, __be32 *p) 1191 { 1192 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 1193 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1194 __be32 seq; 1195 struct kvec iov; 1196 struct xdr_buf verf_buf; 1197 struct xdr_netobj mic; 1198 u32 flav,len; 1199 u32 maj_stat; 1200 1201 dprintk("RPC: %5u gss_validate\n", task->tk_pid); 1202 1203 flav = ntohl(*p++); 1204 if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE) 1205 goto out_bad; 1206 if (flav != RPC_AUTH_GSS) 1207 goto out_bad; 1208 seq = htonl(task->tk_rqstp->rq_seqno); 1209 iov.iov_base = &seq; 1210 iov.iov_len = sizeof(seq); 1211 xdr_buf_from_iov(&iov, &verf_buf); 1212 mic.data = (u8 *)p; 1213 mic.len = len; 1214 1215 maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic); 1216 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1217 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1218 if (maj_stat) { 1219 dprintk("RPC: %5u gss_validate: gss_verify_mic returned " 1220 "error 0x%08x\n", task->tk_pid, maj_stat); 1221 goto out_bad; 1222 } 1223 /* We leave it to unwrap to calculate au_rslack. For now we just 1224 * calculate the length of the verifier: */ 1225 cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2; 1226 gss_put_ctx(ctx); 1227 dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n", 1228 task->tk_pid); 1229 return p + XDR_QUADLEN(len); 1230 out_bad: 1231 gss_put_ctx(ctx); 1232 dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid); 1233 return NULL; 1234 } 1235 1236 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp, 1237 __be32 *p, void *obj) 1238 { 1239 struct xdr_stream xdr; 1240 1241 xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p); 1242 encode(rqstp, &xdr, obj); 1243 } 1244 1245 static inline int 1246 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1247 kxdreproc_t encode, struct rpc_rqst *rqstp, 1248 __be32 *p, void *obj) 1249 { 1250 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 1251 struct xdr_buf integ_buf; 1252 __be32 *integ_len = NULL; 1253 struct xdr_netobj mic; 1254 u32 offset; 1255 __be32 *q; 1256 struct kvec *iov; 1257 u32 maj_stat = 0; 1258 int status = -EIO; 1259 1260 integ_len = p++; 1261 offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; 1262 *p++ = htonl(rqstp->rq_seqno); 1263 1264 gss_wrap_req_encode(encode, rqstp, p, obj); 1265 1266 if (xdr_buf_subsegment(snd_buf, &integ_buf, 1267 offset, snd_buf->len - offset)) 1268 return status; 1269 *integ_len = htonl(integ_buf.len); 1270 1271 /* guess whether we're in the head or the tail: */ 1272 if (snd_buf->page_len || snd_buf->tail[0].iov_len) 1273 iov = snd_buf->tail; 1274 else 1275 iov = snd_buf->head; 1276 p = iov->iov_base + iov->iov_len; 1277 mic.data = (u8 *)(p + 1); 1278 1279 maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic); 1280 status = -EIO; /* XXX? */ 1281 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1282 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1283 else if (maj_stat) 1284 return status; 1285 q = xdr_encode_opaque(p, NULL, mic.len); 1286 1287 offset = (u8 *)q - (u8 *)p; 1288 iov->iov_len += offset; 1289 snd_buf->len += offset; 1290 return 0; 1291 } 1292 1293 static void 1294 priv_release_snd_buf(struct rpc_rqst *rqstp) 1295 { 1296 int i; 1297 1298 for (i=0; i < rqstp->rq_enc_pages_num; i++) 1299 __free_page(rqstp->rq_enc_pages[i]); 1300 kfree(rqstp->rq_enc_pages); 1301 } 1302 1303 static int 1304 alloc_enc_pages(struct rpc_rqst *rqstp) 1305 { 1306 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 1307 int first, last, i; 1308 1309 if (snd_buf->page_len == 0) { 1310 rqstp->rq_enc_pages_num = 0; 1311 return 0; 1312 } 1313 1314 first = snd_buf->page_base >> PAGE_CACHE_SHIFT; 1315 last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT; 1316 rqstp->rq_enc_pages_num = last - first + 1 + 1; 1317 rqstp->rq_enc_pages 1318 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *), 1319 GFP_NOFS); 1320 if (!rqstp->rq_enc_pages) 1321 goto out; 1322 for (i=0; i < rqstp->rq_enc_pages_num; i++) { 1323 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS); 1324 if (rqstp->rq_enc_pages[i] == NULL) 1325 goto out_free; 1326 } 1327 rqstp->rq_release_snd_buf = priv_release_snd_buf; 1328 return 0; 1329 out_free: 1330 rqstp->rq_enc_pages_num = i; 1331 priv_release_snd_buf(rqstp); 1332 out: 1333 return -EAGAIN; 1334 } 1335 1336 static inline int 1337 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1338 kxdreproc_t encode, struct rpc_rqst *rqstp, 1339 __be32 *p, void *obj) 1340 { 1341 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 1342 u32 offset; 1343 u32 maj_stat; 1344 int status; 1345 __be32 *opaque_len; 1346 struct page **inpages; 1347 int first; 1348 int pad; 1349 struct kvec *iov; 1350 char *tmp; 1351 1352 opaque_len = p++; 1353 offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; 1354 *p++ = htonl(rqstp->rq_seqno); 1355 1356 gss_wrap_req_encode(encode, rqstp, p, obj); 1357 1358 status = alloc_enc_pages(rqstp); 1359 if (status) 1360 return status; 1361 first = snd_buf->page_base >> PAGE_CACHE_SHIFT; 1362 inpages = snd_buf->pages + first; 1363 snd_buf->pages = rqstp->rq_enc_pages; 1364 snd_buf->page_base -= first << PAGE_CACHE_SHIFT; 1365 /* 1366 * Give the tail its own page, in case we need extra space in the 1367 * head when wrapping: 1368 * 1369 * call_allocate() allocates twice the slack space required 1370 * by the authentication flavor to rq_callsize. 1371 * For GSS, slack is GSS_CRED_SLACK. 1372 */ 1373 if (snd_buf->page_len || snd_buf->tail[0].iov_len) { 1374 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]); 1375 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len); 1376 snd_buf->tail[0].iov_base = tmp; 1377 } 1378 maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages); 1379 /* slack space should prevent this ever happening: */ 1380 BUG_ON(snd_buf->len > snd_buf->buflen); 1381 status = -EIO; 1382 /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was 1383 * done anyway, so it's safe to put the request on the wire: */ 1384 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1385 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1386 else if (maj_stat) 1387 return status; 1388 1389 *opaque_len = htonl(snd_buf->len - offset); 1390 /* guess whether we're in the head or the tail: */ 1391 if (snd_buf->page_len || snd_buf->tail[0].iov_len) 1392 iov = snd_buf->tail; 1393 else 1394 iov = snd_buf->head; 1395 p = iov->iov_base + iov->iov_len; 1396 pad = 3 - ((snd_buf->len - offset - 1) & 3); 1397 memset(p, 0, pad); 1398 iov->iov_len += pad; 1399 snd_buf->len += pad; 1400 1401 return 0; 1402 } 1403 1404 static int 1405 gss_wrap_req(struct rpc_task *task, 1406 kxdreproc_t encode, void *rqstp, __be32 *p, void *obj) 1407 { 1408 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 1409 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 1410 gc_base); 1411 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1412 int status = -EIO; 1413 1414 dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid); 1415 if (ctx->gc_proc != RPC_GSS_PROC_DATA) { 1416 /* The spec seems a little ambiguous here, but I think that not 1417 * wrapping context destruction requests makes the most sense. 1418 */ 1419 gss_wrap_req_encode(encode, rqstp, p, obj); 1420 status = 0; 1421 goto out; 1422 } 1423 switch (gss_cred->gc_service) { 1424 case RPC_GSS_SVC_NONE: 1425 gss_wrap_req_encode(encode, rqstp, p, obj); 1426 status = 0; 1427 break; 1428 case RPC_GSS_SVC_INTEGRITY: 1429 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj); 1430 break; 1431 case RPC_GSS_SVC_PRIVACY: 1432 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj); 1433 break; 1434 } 1435 out: 1436 gss_put_ctx(ctx); 1437 dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status); 1438 return status; 1439 } 1440 1441 static inline int 1442 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1443 struct rpc_rqst *rqstp, __be32 **p) 1444 { 1445 struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; 1446 struct xdr_buf integ_buf; 1447 struct xdr_netobj mic; 1448 u32 data_offset, mic_offset; 1449 u32 integ_len; 1450 u32 maj_stat; 1451 int status = -EIO; 1452 1453 integ_len = ntohl(*(*p)++); 1454 if (integ_len & 3) 1455 return status; 1456 data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base; 1457 mic_offset = integ_len + data_offset; 1458 if (mic_offset > rcv_buf->len) 1459 return status; 1460 if (ntohl(*(*p)++) != rqstp->rq_seqno) 1461 return status; 1462 1463 if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset, 1464 mic_offset - data_offset)) 1465 return status; 1466 1467 if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset)) 1468 return status; 1469 1470 maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic); 1471 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1472 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1473 if (maj_stat != GSS_S_COMPLETE) 1474 return status; 1475 return 0; 1476 } 1477 1478 static inline int 1479 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1480 struct rpc_rqst *rqstp, __be32 **p) 1481 { 1482 struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; 1483 u32 offset; 1484 u32 opaque_len; 1485 u32 maj_stat; 1486 int status = -EIO; 1487 1488 opaque_len = ntohl(*(*p)++); 1489 offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base; 1490 if (offset + opaque_len > rcv_buf->len) 1491 return status; 1492 /* remove padding: */ 1493 rcv_buf->len = offset + opaque_len; 1494 1495 maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf); 1496 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1497 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1498 if (maj_stat != GSS_S_COMPLETE) 1499 return status; 1500 if (ntohl(*(*p)++) != rqstp->rq_seqno) 1501 return status; 1502 1503 return 0; 1504 } 1505 1506 static int 1507 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp, 1508 __be32 *p, void *obj) 1509 { 1510 struct xdr_stream xdr; 1511 1512 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); 1513 return decode(rqstp, &xdr, obj); 1514 } 1515 1516 static int 1517 gss_unwrap_resp(struct rpc_task *task, 1518 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj) 1519 { 1520 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 1521 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 1522 gc_base); 1523 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1524 __be32 *savedp = p; 1525 struct kvec *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head; 1526 int savedlen = head->iov_len; 1527 int status = -EIO; 1528 1529 if (ctx->gc_proc != RPC_GSS_PROC_DATA) 1530 goto out_decode; 1531 switch (gss_cred->gc_service) { 1532 case RPC_GSS_SVC_NONE: 1533 break; 1534 case RPC_GSS_SVC_INTEGRITY: 1535 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p); 1536 if (status) 1537 goto out; 1538 break; 1539 case RPC_GSS_SVC_PRIVACY: 1540 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p); 1541 if (status) 1542 goto out; 1543 break; 1544 } 1545 /* take into account extra slack for integrity and privacy cases: */ 1546 cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp) 1547 + (savedlen - head->iov_len); 1548 out_decode: 1549 status = gss_unwrap_req_decode(decode, rqstp, p, obj); 1550 out: 1551 gss_put_ctx(ctx); 1552 dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid, 1553 status); 1554 return status; 1555 } 1556 1557 static const struct rpc_authops authgss_ops = { 1558 .owner = THIS_MODULE, 1559 .au_flavor = RPC_AUTH_GSS, 1560 .au_name = "RPCSEC_GSS", 1561 .create = gss_create, 1562 .destroy = gss_destroy, 1563 .lookup_cred = gss_lookup_cred, 1564 .crcreate = gss_create_cred 1565 }; 1566 1567 static const struct rpc_credops gss_credops = { 1568 .cr_name = "AUTH_GSS", 1569 .crdestroy = gss_destroy_cred, 1570 .cr_init = gss_cred_init, 1571 .crbind = rpcauth_generic_bind_cred, 1572 .crmatch = gss_match, 1573 .crmarshal = gss_marshal, 1574 .crrefresh = gss_refresh, 1575 .crvalidate = gss_validate, 1576 .crwrap_req = gss_wrap_req, 1577 .crunwrap_resp = gss_unwrap_resp, 1578 }; 1579 1580 static const struct rpc_credops gss_nullops = { 1581 .cr_name = "AUTH_GSS", 1582 .crdestroy = gss_destroy_nullcred, 1583 .crbind = rpcauth_generic_bind_cred, 1584 .crmatch = gss_match, 1585 .crmarshal = gss_marshal, 1586 .crrefresh = gss_refresh_null, 1587 .crvalidate = gss_validate, 1588 .crwrap_req = gss_wrap_req, 1589 .crunwrap_resp = gss_unwrap_resp, 1590 }; 1591 1592 static const struct rpc_pipe_ops gss_upcall_ops_v0 = { 1593 .upcall = gss_pipe_upcall, 1594 .downcall = gss_pipe_downcall, 1595 .destroy_msg = gss_pipe_destroy_msg, 1596 .open_pipe = gss_pipe_open_v0, 1597 .release_pipe = gss_pipe_release, 1598 }; 1599 1600 static const struct rpc_pipe_ops gss_upcall_ops_v1 = { 1601 .upcall = gss_pipe_upcall, 1602 .downcall = gss_pipe_downcall, 1603 .destroy_msg = gss_pipe_destroy_msg, 1604 .open_pipe = gss_pipe_open_v1, 1605 .release_pipe = gss_pipe_release, 1606 }; 1607 1608 /* 1609 * Initialize RPCSEC_GSS module 1610 */ 1611 static int __init init_rpcsec_gss(void) 1612 { 1613 int err = 0; 1614 1615 err = rpcauth_register(&authgss_ops); 1616 if (err) 1617 goto out; 1618 err = gss_svc_init(); 1619 if (err) 1620 goto out_unregister; 1621 rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version"); 1622 return 0; 1623 out_unregister: 1624 rpcauth_unregister(&authgss_ops); 1625 out: 1626 return err; 1627 } 1628 1629 static void __exit exit_rpcsec_gss(void) 1630 { 1631 gss_svc_shutdown(); 1632 rpcauth_unregister(&authgss_ops); 1633 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1634 } 1635 1636 MODULE_LICENSE("GPL"); 1637 module_param_named(expired_cred_retry_delay, 1638 gss_expired_cred_retry_delay, 1639 uint, 0644); 1640 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until " 1641 "the RPC engine retries an expired credential"); 1642 1643 module_init(init_rpcsec_gss) 1644 module_exit(exit_rpcsec_gss) 1645