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, 396 const char *service_name) 397 { 398 struct gss_api_mech *mech = gss_msg->auth->mech; 399 char *p = gss_msg->databuf; 400 int len = 0; 401 402 gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ", 403 mech->gm_name, 404 gss_msg->uid); 405 p += gss_msg->msg.len; 406 if (clnt->cl_principal) { 407 len = sprintf(p, "target=%s ", clnt->cl_principal); 408 p += len; 409 gss_msg->msg.len += len; 410 } 411 if (service_name != NULL) { 412 len = sprintf(p, "service=%s ", service_name); 413 p += len; 414 gss_msg->msg.len += len; 415 } 416 if (mech->gm_upcall_enctypes) { 417 len = sprintf(p, "enctypes=%s ", mech->gm_upcall_enctypes); 418 p += len; 419 gss_msg->msg.len += len; 420 } 421 len = sprintf(p, "\n"); 422 gss_msg->msg.len += len; 423 424 gss_msg->msg.data = gss_msg->databuf; 425 BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN); 426 } 427 428 static void gss_encode_msg(struct gss_upcall_msg *gss_msg, 429 struct rpc_clnt *clnt, 430 const char *service_name) 431 { 432 if (pipe_version == 0) 433 gss_encode_v0_msg(gss_msg); 434 else /* pipe_version == 1 */ 435 gss_encode_v1_msg(gss_msg, clnt, service_name); 436 } 437 438 static struct gss_upcall_msg * 439 gss_alloc_msg(struct gss_auth *gss_auth, struct rpc_clnt *clnt, 440 uid_t uid, const char *service_name) 441 { 442 struct gss_upcall_msg *gss_msg; 443 int vers; 444 445 gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS); 446 if (gss_msg == NULL) 447 return ERR_PTR(-ENOMEM); 448 vers = get_pipe_version(); 449 if (vers < 0) { 450 kfree(gss_msg); 451 return ERR_PTR(vers); 452 } 453 gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode); 454 INIT_LIST_HEAD(&gss_msg->list); 455 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq"); 456 init_waitqueue_head(&gss_msg->waitqueue); 457 atomic_set(&gss_msg->count, 1); 458 gss_msg->uid = uid; 459 gss_msg->auth = gss_auth; 460 gss_encode_msg(gss_msg, clnt, service_name); 461 return gss_msg; 462 } 463 464 static struct gss_upcall_msg * 465 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred) 466 { 467 struct gss_cred *gss_cred = container_of(cred, 468 struct gss_cred, gc_base); 469 struct gss_upcall_msg *gss_new, *gss_msg; 470 uid_t uid = cred->cr_uid; 471 472 gss_new = gss_alloc_msg(gss_auth, clnt, uid, gss_cred->gc_principal); 473 if (IS_ERR(gss_new)) 474 return gss_new; 475 gss_msg = gss_add_msg(gss_new); 476 if (gss_msg == gss_new) { 477 struct inode *inode = &gss_new->inode->vfs_inode; 478 int res = rpc_queue_upcall(inode, &gss_new->msg); 479 if (res) { 480 gss_unhash_msg(gss_new); 481 gss_msg = ERR_PTR(res); 482 } 483 } else 484 gss_release_msg(gss_new); 485 return gss_msg; 486 } 487 488 static void warn_gssd(void) 489 { 490 static unsigned long ratelimit; 491 unsigned long now = jiffies; 492 493 if (time_after(now, ratelimit)) { 494 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n" 495 "Please check user daemon is running.\n"); 496 ratelimit = now + 15*HZ; 497 } 498 } 499 500 static inline int 501 gss_refresh_upcall(struct rpc_task *task) 502 { 503 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 504 struct gss_auth *gss_auth = container_of(cred->cr_auth, 505 struct gss_auth, rpc_auth); 506 struct gss_cred *gss_cred = container_of(cred, 507 struct gss_cred, gc_base); 508 struct gss_upcall_msg *gss_msg; 509 struct inode *inode; 510 int err = 0; 511 512 dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid, 513 cred->cr_uid); 514 gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred); 515 if (PTR_ERR(gss_msg) == -EAGAIN) { 516 /* XXX: warning on the first, under the assumption we 517 * shouldn't normally hit this case on a refresh. */ 518 warn_gssd(); 519 task->tk_timeout = 15*HZ; 520 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL); 521 return -EAGAIN; 522 } 523 if (IS_ERR(gss_msg)) { 524 err = PTR_ERR(gss_msg); 525 goto out; 526 } 527 inode = &gss_msg->inode->vfs_inode; 528 spin_lock(&inode->i_lock); 529 if (gss_cred->gc_upcall != NULL) 530 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL); 531 else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) { 532 task->tk_timeout = 0; 533 gss_cred->gc_upcall = gss_msg; 534 /* gss_upcall_callback will release the reference to gss_upcall_msg */ 535 atomic_inc(&gss_msg->count); 536 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback); 537 } else { 538 gss_handle_downcall_result(gss_cred, gss_msg); 539 err = gss_msg->msg.errno; 540 } 541 spin_unlock(&inode->i_lock); 542 gss_release_msg(gss_msg); 543 out: 544 dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n", 545 task->tk_pid, cred->cr_uid, err); 546 return err; 547 } 548 549 static inline int 550 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred) 551 { 552 struct inode *inode; 553 struct rpc_cred *cred = &gss_cred->gc_base; 554 struct gss_upcall_msg *gss_msg; 555 DEFINE_WAIT(wait); 556 int err = 0; 557 558 dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid); 559 retry: 560 gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred); 561 if (PTR_ERR(gss_msg) == -EAGAIN) { 562 err = wait_event_interruptible_timeout(pipe_version_waitqueue, 563 pipe_version >= 0, 15*HZ); 564 if (pipe_version < 0) { 565 warn_gssd(); 566 err = -EACCES; 567 } 568 if (err) 569 goto out; 570 goto retry; 571 } 572 if (IS_ERR(gss_msg)) { 573 err = PTR_ERR(gss_msg); 574 goto out; 575 } 576 inode = &gss_msg->inode->vfs_inode; 577 for (;;) { 578 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE); 579 spin_lock(&inode->i_lock); 580 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) { 581 break; 582 } 583 spin_unlock(&inode->i_lock); 584 if (fatal_signal_pending(current)) { 585 err = -ERESTARTSYS; 586 goto out_intr; 587 } 588 schedule(); 589 } 590 if (gss_msg->ctx) 591 gss_cred_set_ctx(cred, gss_msg->ctx); 592 else 593 err = gss_msg->msg.errno; 594 spin_unlock(&inode->i_lock); 595 out_intr: 596 finish_wait(&gss_msg->waitqueue, &wait); 597 gss_release_msg(gss_msg); 598 out: 599 dprintk("RPC: gss_create_upcall for uid %u result %d\n", 600 cred->cr_uid, err); 601 return err; 602 } 603 604 #define MSG_BUF_MAXSIZE 1024 605 606 static ssize_t 607 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) 608 { 609 const void *p, *end; 610 void *buf; 611 struct gss_upcall_msg *gss_msg; 612 struct inode *inode = filp->f_path.dentry->d_inode; 613 struct gss_cl_ctx *ctx; 614 uid_t uid; 615 ssize_t err = -EFBIG; 616 617 if (mlen > MSG_BUF_MAXSIZE) 618 goto out; 619 err = -ENOMEM; 620 buf = kmalloc(mlen, GFP_NOFS); 621 if (!buf) 622 goto out; 623 624 err = -EFAULT; 625 if (copy_from_user(buf, src, mlen)) 626 goto err; 627 628 end = (const void *)((char *)buf + mlen); 629 p = simple_get_bytes(buf, end, &uid, sizeof(uid)); 630 if (IS_ERR(p)) { 631 err = PTR_ERR(p); 632 goto err; 633 } 634 635 err = -ENOMEM; 636 ctx = gss_alloc_context(); 637 if (ctx == NULL) 638 goto err; 639 640 err = -ENOENT; 641 /* Find a matching upcall */ 642 spin_lock(&inode->i_lock); 643 gss_msg = __gss_find_upcall(RPC_I(inode), uid); 644 if (gss_msg == NULL) { 645 spin_unlock(&inode->i_lock); 646 goto err_put_ctx; 647 } 648 list_del_init(&gss_msg->list); 649 spin_unlock(&inode->i_lock); 650 651 p = gss_fill_context(p, end, ctx, gss_msg->auth->mech); 652 if (IS_ERR(p)) { 653 err = PTR_ERR(p); 654 switch (err) { 655 case -EACCES: 656 case -EKEYEXPIRED: 657 gss_msg->msg.errno = err; 658 err = mlen; 659 break; 660 case -EFAULT: 661 case -ENOMEM: 662 case -EINVAL: 663 case -ENOSYS: 664 gss_msg->msg.errno = -EAGAIN; 665 break; 666 default: 667 printk(KERN_CRIT "%s: bad return from " 668 "gss_fill_context: %zd\n", __func__, err); 669 BUG(); 670 } 671 goto err_release_msg; 672 } 673 gss_msg->ctx = gss_get_ctx(ctx); 674 err = mlen; 675 676 err_release_msg: 677 spin_lock(&inode->i_lock); 678 __gss_unhash_msg(gss_msg); 679 spin_unlock(&inode->i_lock); 680 gss_release_msg(gss_msg); 681 err_put_ctx: 682 gss_put_ctx(ctx); 683 err: 684 kfree(buf); 685 out: 686 dprintk("RPC: gss_pipe_downcall returning %Zd\n", err); 687 return err; 688 } 689 690 static int gss_pipe_open(struct inode *inode, int new_version) 691 { 692 int ret = 0; 693 694 spin_lock(&pipe_version_lock); 695 if (pipe_version < 0) { 696 /* First open of any gss pipe determines the version: */ 697 pipe_version = new_version; 698 rpc_wake_up(&pipe_version_rpc_waitqueue); 699 wake_up(&pipe_version_waitqueue); 700 } else if (pipe_version != new_version) { 701 /* Trying to open a pipe of a different version */ 702 ret = -EBUSY; 703 goto out; 704 } 705 atomic_inc(&pipe_users); 706 out: 707 spin_unlock(&pipe_version_lock); 708 return ret; 709 710 } 711 712 static int gss_pipe_open_v0(struct inode *inode) 713 { 714 return gss_pipe_open(inode, 0); 715 } 716 717 static int gss_pipe_open_v1(struct inode *inode) 718 { 719 return gss_pipe_open(inode, 1); 720 } 721 722 static void 723 gss_pipe_release(struct inode *inode) 724 { 725 struct rpc_inode *rpci = RPC_I(inode); 726 struct gss_upcall_msg *gss_msg; 727 728 restart: 729 spin_lock(&inode->i_lock); 730 list_for_each_entry(gss_msg, &rpci->in_downcall, list) { 731 732 if (!list_empty(&gss_msg->msg.list)) 733 continue; 734 gss_msg->msg.errno = -EPIPE; 735 atomic_inc(&gss_msg->count); 736 __gss_unhash_msg(gss_msg); 737 spin_unlock(&inode->i_lock); 738 gss_release_msg(gss_msg); 739 goto restart; 740 } 741 spin_unlock(&inode->i_lock); 742 743 put_pipe_version(); 744 } 745 746 static void 747 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg) 748 { 749 struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg); 750 751 if (msg->errno < 0) { 752 dprintk("RPC: gss_pipe_destroy_msg releasing msg %p\n", 753 gss_msg); 754 atomic_inc(&gss_msg->count); 755 gss_unhash_msg(gss_msg); 756 if (msg->errno == -ETIMEDOUT) 757 warn_gssd(); 758 gss_release_msg(gss_msg); 759 } 760 } 761 762 /* 763 * NOTE: we have the opportunity to use different 764 * parameters based on the input flavor (which must be a pseudoflavor) 765 */ 766 static struct rpc_auth * 767 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor) 768 { 769 struct gss_auth *gss_auth; 770 struct rpc_auth * auth; 771 int err = -ENOMEM; /* XXX? */ 772 773 dprintk("RPC: creating GSS authenticator for client %p\n", clnt); 774 775 if (!try_module_get(THIS_MODULE)) 776 return ERR_PTR(err); 777 if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL))) 778 goto out_dec; 779 gss_auth->client = clnt; 780 err = -EINVAL; 781 gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor); 782 if (!gss_auth->mech) { 783 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n", 784 __func__, flavor); 785 goto err_free; 786 } 787 gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor); 788 if (gss_auth->service == 0) 789 goto err_put_mech; 790 auth = &gss_auth->rpc_auth; 791 auth->au_cslack = GSS_CRED_SLACK >> 2; 792 auth->au_rslack = GSS_VERF_SLACK >> 2; 793 auth->au_ops = &authgss_ops; 794 auth->au_flavor = flavor; 795 atomic_set(&auth->au_count, 1); 796 kref_init(&gss_auth->kref); 797 798 /* 799 * Note: if we created the old pipe first, then someone who 800 * examined the directory at the right moment might conclude 801 * that we supported only the old pipe. So we instead create 802 * the new pipe first. 803 */ 804 gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry, 805 "gssd", 806 clnt, &gss_upcall_ops_v1, 807 RPC_PIPE_WAIT_FOR_OPEN); 808 if (IS_ERR(gss_auth->dentry[1])) { 809 err = PTR_ERR(gss_auth->dentry[1]); 810 goto err_put_mech; 811 } 812 813 gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry, 814 gss_auth->mech->gm_name, 815 clnt, &gss_upcall_ops_v0, 816 RPC_PIPE_WAIT_FOR_OPEN); 817 if (IS_ERR(gss_auth->dentry[0])) { 818 err = PTR_ERR(gss_auth->dentry[0]); 819 goto err_unlink_pipe_1; 820 } 821 err = rpcauth_init_credcache(auth); 822 if (err) 823 goto err_unlink_pipe_0; 824 825 return auth; 826 err_unlink_pipe_0: 827 rpc_unlink(gss_auth->dentry[0]); 828 err_unlink_pipe_1: 829 rpc_unlink(gss_auth->dentry[1]); 830 err_put_mech: 831 gss_mech_put(gss_auth->mech); 832 err_free: 833 kfree(gss_auth); 834 out_dec: 835 module_put(THIS_MODULE); 836 return ERR_PTR(err); 837 } 838 839 static void 840 gss_free(struct gss_auth *gss_auth) 841 { 842 rpc_unlink(gss_auth->dentry[1]); 843 rpc_unlink(gss_auth->dentry[0]); 844 gss_mech_put(gss_auth->mech); 845 846 kfree(gss_auth); 847 module_put(THIS_MODULE); 848 } 849 850 static void 851 gss_free_callback(struct kref *kref) 852 { 853 struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref); 854 855 gss_free(gss_auth); 856 } 857 858 static void 859 gss_destroy(struct rpc_auth *auth) 860 { 861 struct gss_auth *gss_auth; 862 863 dprintk("RPC: destroying GSS authenticator %p flavor %d\n", 864 auth, auth->au_flavor); 865 866 rpcauth_destroy_credcache(auth); 867 868 gss_auth = container_of(auth, struct gss_auth, rpc_auth); 869 kref_put(&gss_auth->kref, gss_free_callback); 870 } 871 872 /* 873 * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call 874 * to the server with the GSS control procedure field set to 875 * RPC_GSS_PROC_DESTROY. This should normally cause the server to release 876 * all RPCSEC_GSS state associated with that context. 877 */ 878 static int 879 gss_destroying_context(struct rpc_cred *cred) 880 { 881 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 882 struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth); 883 struct rpc_task *task; 884 885 if (gss_cred->gc_ctx == NULL || 886 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0) 887 return 0; 888 889 gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY; 890 cred->cr_ops = &gss_nullops; 891 892 /* Take a reference to ensure the cred will be destroyed either 893 * by the RPC call or by the put_rpccred() below */ 894 get_rpccred(cred); 895 896 task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT); 897 if (!IS_ERR(task)) 898 rpc_put_task(task); 899 900 put_rpccred(cred); 901 return 1; 902 } 903 904 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure 905 * to create a new cred or context, so they check that things have been 906 * allocated before freeing them. */ 907 static void 908 gss_do_free_ctx(struct gss_cl_ctx *ctx) 909 { 910 dprintk("RPC: gss_free_ctx\n"); 911 912 gss_delete_sec_context(&ctx->gc_gss_ctx); 913 kfree(ctx->gc_wire_ctx.data); 914 kfree(ctx); 915 } 916 917 static void 918 gss_free_ctx_callback(struct rcu_head *head) 919 { 920 struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu); 921 gss_do_free_ctx(ctx); 922 } 923 924 static void 925 gss_free_ctx(struct gss_cl_ctx *ctx) 926 { 927 call_rcu(&ctx->gc_rcu, gss_free_ctx_callback); 928 } 929 930 static void 931 gss_free_cred(struct gss_cred *gss_cred) 932 { 933 dprintk("RPC: gss_free_cred %p\n", gss_cred); 934 kfree(gss_cred); 935 } 936 937 static void 938 gss_free_cred_callback(struct rcu_head *head) 939 { 940 struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu); 941 gss_free_cred(gss_cred); 942 } 943 944 static void 945 gss_destroy_nullcred(struct rpc_cred *cred) 946 { 947 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 948 struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth); 949 struct gss_cl_ctx *ctx = gss_cred->gc_ctx; 950 951 RCU_INIT_POINTER(gss_cred->gc_ctx, NULL); 952 call_rcu(&cred->cr_rcu, gss_free_cred_callback); 953 if (ctx) 954 gss_put_ctx(ctx); 955 kref_put(&gss_auth->kref, gss_free_callback); 956 } 957 958 static void 959 gss_destroy_cred(struct rpc_cred *cred) 960 { 961 962 if (gss_destroying_context(cred)) 963 return; 964 gss_destroy_nullcred(cred); 965 } 966 967 /* 968 * Lookup RPCSEC_GSS cred for the current process 969 */ 970 static struct rpc_cred * 971 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 972 { 973 return rpcauth_lookup_credcache(auth, acred, flags); 974 } 975 976 static struct rpc_cred * 977 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 978 { 979 struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); 980 struct gss_cred *cred = NULL; 981 int err = -ENOMEM; 982 983 dprintk("RPC: gss_create_cred for uid %d, flavor %d\n", 984 acred->uid, auth->au_flavor); 985 986 if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS))) 987 goto out_err; 988 989 rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops); 990 /* 991 * Note: in order to force a call to call_refresh(), we deliberately 992 * fail to flag the credential as RPCAUTH_CRED_UPTODATE. 993 */ 994 cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW; 995 cred->gc_service = gss_auth->service; 996 cred->gc_principal = NULL; 997 if (acred->machine_cred) 998 cred->gc_principal = acred->principal; 999 kref_get(&gss_auth->kref); 1000 return &cred->gc_base; 1001 1002 out_err: 1003 dprintk("RPC: gss_create_cred failed with error %d\n", err); 1004 return ERR_PTR(err); 1005 } 1006 1007 static int 1008 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred) 1009 { 1010 struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); 1011 struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base); 1012 int err; 1013 1014 do { 1015 err = gss_create_upcall(gss_auth, gss_cred); 1016 } while (err == -EAGAIN); 1017 return err; 1018 } 1019 1020 static int 1021 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags) 1022 { 1023 struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base); 1024 1025 if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags)) 1026 goto out; 1027 /* Don't match with creds that have expired. */ 1028 if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry)) 1029 return 0; 1030 if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags)) 1031 return 0; 1032 out: 1033 if (acred->principal != NULL) { 1034 if (gss_cred->gc_principal == NULL) 1035 return 0; 1036 return strcmp(acred->principal, gss_cred->gc_principal) == 0; 1037 } 1038 if (gss_cred->gc_principal != NULL) 1039 return 0; 1040 return rc->cr_uid == acred->uid; 1041 } 1042 1043 /* 1044 * Marshal credentials. 1045 * Maybe we should keep a cached credential for performance reasons. 1046 */ 1047 static __be32 * 1048 gss_marshal(struct rpc_task *task, __be32 *p) 1049 { 1050 struct rpc_rqst *req = task->tk_rqstp; 1051 struct rpc_cred *cred = req->rq_cred; 1052 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 1053 gc_base); 1054 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1055 __be32 *cred_len; 1056 u32 maj_stat = 0; 1057 struct xdr_netobj mic; 1058 struct kvec iov; 1059 struct xdr_buf verf_buf; 1060 1061 dprintk("RPC: %5u gss_marshal\n", task->tk_pid); 1062 1063 *p++ = htonl(RPC_AUTH_GSS); 1064 cred_len = p++; 1065 1066 spin_lock(&ctx->gc_seq_lock); 1067 req->rq_seqno = ctx->gc_seq++; 1068 spin_unlock(&ctx->gc_seq_lock); 1069 1070 *p++ = htonl((u32) RPC_GSS_VERSION); 1071 *p++ = htonl((u32) ctx->gc_proc); 1072 *p++ = htonl((u32) req->rq_seqno); 1073 *p++ = htonl((u32) gss_cred->gc_service); 1074 p = xdr_encode_netobj(p, &ctx->gc_wire_ctx); 1075 *cred_len = htonl((p - (cred_len + 1)) << 2); 1076 1077 /* We compute the checksum for the verifier over the xdr-encoded bytes 1078 * starting with the xid and ending at the end of the credential: */ 1079 iov.iov_base = xprt_skip_transport_header(task->tk_xprt, 1080 req->rq_snd_buf.head[0].iov_base); 1081 iov.iov_len = (u8 *)p - (u8 *)iov.iov_base; 1082 xdr_buf_from_iov(&iov, &verf_buf); 1083 1084 /* set verifier flavor*/ 1085 *p++ = htonl(RPC_AUTH_GSS); 1086 1087 mic.data = (u8 *)(p + 1); 1088 maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic); 1089 if (maj_stat == GSS_S_CONTEXT_EXPIRED) { 1090 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1091 } else if (maj_stat != 0) { 1092 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat); 1093 goto out_put_ctx; 1094 } 1095 p = xdr_encode_opaque(p, NULL, mic.len); 1096 gss_put_ctx(ctx); 1097 return p; 1098 out_put_ctx: 1099 gss_put_ctx(ctx); 1100 return NULL; 1101 } 1102 1103 static int gss_renew_cred(struct rpc_task *task) 1104 { 1105 struct rpc_cred *oldcred = task->tk_rqstp->rq_cred; 1106 struct gss_cred *gss_cred = container_of(oldcred, 1107 struct gss_cred, 1108 gc_base); 1109 struct rpc_auth *auth = oldcred->cr_auth; 1110 struct auth_cred acred = { 1111 .uid = oldcred->cr_uid, 1112 .principal = gss_cred->gc_principal, 1113 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0), 1114 }; 1115 struct rpc_cred *new; 1116 1117 new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW); 1118 if (IS_ERR(new)) 1119 return PTR_ERR(new); 1120 task->tk_rqstp->rq_cred = new; 1121 put_rpccred(oldcred); 1122 return 0; 1123 } 1124 1125 static int gss_cred_is_negative_entry(struct rpc_cred *cred) 1126 { 1127 if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) { 1128 unsigned long now = jiffies; 1129 unsigned long begin, expire; 1130 struct gss_cred *gss_cred; 1131 1132 gss_cred = container_of(cred, struct gss_cred, gc_base); 1133 begin = gss_cred->gc_upcall_timestamp; 1134 expire = begin + gss_expired_cred_retry_delay * HZ; 1135 1136 if (time_in_range_open(now, begin, expire)) 1137 return 1; 1138 } 1139 return 0; 1140 } 1141 1142 /* 1143 * Refresh credentials. XXX - finish 1144 */ 1145 static int 1146 gss_refresh(struct rpc_task *task) 1147 { 1148 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 1149 int ret = 0; 1150 1151 if (gss_cred_is_negative_entry(cred)) 1152 return -EKEYEXPIRED; 1153 1154 if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) && 1155 !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) { 1156 ret = gss_renew_cred(task); 1157 if (ret < 0) 1158 goto out; 1159 cred = task->tk_rqstp->rq_cred; 1160 } 1161 1162 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)) 1163 ret = gss_refresh_upcall(task); 1164 out: 1165 return ret; 1166 } 1167 1168 /* Dummy refresh routine: used only when destroying the context */ 1169 static int 1170 gss_refresh_null(struct rpc_task *task) 1171 { 1172 return -EACCES; 1173 } 1174 1175 static __be32 * 1176 gss_validate(struct rpc_task *task, __be32 *p) 1177 { 1178 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 1179 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1180 __be32 seq; 1181 struct kvec iov; 1182 struct xdr_buf verf_buf; 1183 struct xdr_netobj mic; 1184 u32 flav,len; 1185 u32 maj_stat; 1186 1187 dprintk("RPC: %5u gss_validate\n", task->tk_pid); 1188 1189 flav = ntohl(*p++); 1190 if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE) 1191 goto out_bad; 1192 if (flav != RPC_AUTH_GSS) 1193 goto out_bad; 1194 seq = htonl(task->tk_rqstp->rq_seqno); 1195 iov.iov_base = &seq; 1196 iov.iov_len = sizeof(seq); 1197 xdr_buf_from_iov(&iov, &verf_buf); 1198 mic.data = (u8 *)p; 1199 mic.len = len; 1200 1201 maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic); 1202 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1203 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1204 if (maj_stat) { 1205 dprintk("RPC: %5u gss_validate: gss_verify_mic returned " 1206 "error 0x%08x\n", task->tk_pid, maj_stat); 1207 goto out_bad; 1208 } 1209 /* We leave it to unwrap to calculate au_rslack. For now we just 1210 * calculate the length of the verifier: */ 1211 cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2; 1212 gss_put_ctx(ctx); 1213 dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n", 1214 task->tk_pid); 1215 return p + XDR_QUADLEN(len); 1216 out_bad: 1217 gss_put_ctx(ctx); 1218 dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid); 1219 return NULL; 1220 } 1221 1222 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp, 1223 __be32 *p, void *obj) 1224 { 1225 struct xdr_stream xdr; 1226 1227 xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p); 1228 encode(rqstp, &xdr, obj); 1229 } 1230 1231 static inline int 1232 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1233 kxdreproc_t encode, struct rpc_rqst *rqstp, 1234 __be32 *p, void *obj) 1235 { 1236 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 1237 struct xdr_buf integ_buf; 1238 __be32 *integ_len = NULL; 1239 struct xdr_netobj mic; 1240 u32 offset; 1241 __be32 *q; 1242 struct kvec *iov; 1243 u32 maj_stat = 0; 1244 int status = -EIO; 1245 1246 integ_len = p++; 1247 offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; 1248 *p++ = htonl(rqstp->rq_seqno); 1249 1250 gss_wrap_req_encode(encode, rqstp, p, obj); 1251 1252 if (xdr_buf_subsegment(snd_buf, &integ_buf, 1253 offset, snd_buf->len - offset)) 1254 return status; 1255 *integ_len = htonl(integ_buf.len); 1256 1257 /* guess whether we're in the head or the tail: */ 1258 if (snd_buf->page_len || snd_buf->tail[0].iov_len) 1259 iov = snd_buf->tail; 1260 else 1261 iov = snd_buf->head; 1262 p = iov->iov_base + iov->iov_len; 1263 mic.data = (u8 *)(p + 1); 1264 1265 maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic); 1266 status = -EIO; /* XXX? */ 1267 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1268 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1269 else if (maj_stat) 1270 return status; 1271 q = xdr_encode_opaque(p, NULL, mic.len); 1272 1273 offset = (u8 *)q - (u8 *)p; 1274 iov->iov_len += offset; 1275 snd_buf->len += offset; 1276 return 0; 1277 } 1278 1279 static void 1280 priv_release_snd_buf(struct rpc_rqst *rqstp) 1281 { 1282 int i; 1283 1284 for (i=0; i < rqstp->rq_enc_pages_num; i++) 1285 __free_page(rqstp->rq_enc_pages[i]); 1286 kfree(rqstp->rq_enc_pages); 1287 } 1288 1289 static int 1290 alloc_enc_pages(struct rpc_rqst *rqstp) 1291 { 1292 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 1293 int first, last, i; 1294 1295 if (snd_buf->page_len == 0) { 1296 rqstp->rq_enc_pages_num = 0; 1297 return 0; 1298 } 1299 1300 first = snd_buf->page_base >> PAGE_CACHE_SHIFT; 1301 last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT; 1302 rqstp->rq_enc_pages_num = last - first + 1 + 1; 1303 rqstp->rq_enc_pages 1304 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *), 1305 GFP_NOFS); 1306 if (!rqstp->rq_enc_pages) 1307 goto out; 1308 for (i=0; i < rqstp->rq_enc_pages_num; i++) { 1309 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS); 1310 if (rqstp->rq_enc_pages[i] == NULL) 1311 goto out_free; 1312 } 1313 rqstp->rq_release_snd_buf = priv_release_snd_buf; 1314 return 0; 1315 out_free: 1316 rqstp->rq_enc_pages_num = i; 1317 priv_release_snd_buf(rqstp); 1318 out: 1319 return -EAGAIN; 1320 } 1321 1322 static inline int 1323 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1324 kxdreproc_t encode, struct rpc_rqst *rqstp, 1325 __be32 *p, void *obj) 1326 { 1327 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 1328 u32 offset; 1329 u32 maj_stat; 1330 int status; 1331 __be32 *opaque_len; 1332 struct page **inpages; 1333 int first; 1334 int pad; 1335 struct kvec *iov; 1336 char *tmp; 1337 1338 opaque_len = p++; 1339 offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; 1340 *p++ = htonl(rqstp->rq_seqno); 1341 1342 gss_wrap_req_encode(encode, rqstp, p, obj); 1343 1344 status = alloc_enc_pages(rqstp); 1345 if (status) 1346 return status; 1347 first = snd_buf->page_base >> PAGE_CACHE_SHIFT; 1348 inpages = snd_buf->pages + first; 1349 snd_buf->pages = rqstp->rq_enc_pages; 1350 snd_buf->page_base -= first << PAGE_CACHE_SHIFT; 1351 /* 1352 * Give the tail its own page, in case we need extra space in the 1353 * head when wrapping: 1354 * 1355 * call_allocate() allocates twice the slack space required 1356 * by the authentication flavor to rq_callsize. 1357 * For GSS, slack is GSS_CRED_SLACK. 1358 */ 1359 if (snd_buf->page_len || snd_buf->tail[0].iov_len) { 1360 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]); 1361 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len); 1362 snd_buf->tail[0].iov_base = tmp; 1363 } 1364 maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages); 1365 /* slack space should prevent this ever happening: */ 1366 BUG_ON(snd_buf->len > snd_buf->buflen); 1367 status = -EIO; 1368 /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was 1369 * done anyway, so it's safe to put the request on the wire: */ 1370 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1371 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1372 else if (maj_stat) 1373 return status; 1374 1375 *opaque_len = htonl(snd_buf->len - offset); 1376 /* guess whether we're in the head or the tail: */ 1377 if (snd_buf->page_len || snd_buf->tail[0].iov_len) 1378 iov = snd_buf->tail; 1379 else 1380 iov = snd_buf->head; 1381 p = iov->iov_base + iov->iov_len; 1382 pad = 3 - ((snd_buf->len - offset - 1) & 3); 1383 memset(p, 0, pad); 1384 iov->iov_len += pad; 1385 snd_buf->len += pad; 1386 1387 return 0; 1388 } 1389 1390 static int 1391 gss_wrap_req(struct rpc_task *task, 1392 kxdreproc_t encode, void *rqstp, __be32 *p, void *obj) 1393 { 1394 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 1395 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 1396 gc_base); 1397 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1398 int status = -EIO; 1399 1400 dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid); 1401 if (ctx->gc_proc != RPC_GSS_PROC_DATA) { 1402 /* The spec seems a little ambiguous here, but I think that not 1403 * wrapping context destruction requests makes the most sense. 1404 */ 1405 gss_wrap_req_encode(encode, rqstp, p, obj); 1406 status = 0; 1407 goto out; 1408 } 1409 switch (gss_cred->gc_service) { 1410 case RPC_GSS_SVC_NONE: 1411 gss_wrap_req_encode(encode, rqstp, p, obj); 1412 status = 0; 1413 break; 1414 case RPC_GSS_SVC_INTEGRITY: 1415 status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj); 1416 break; 1417 case RPC_GSS_SVC_PRIVACY: 1418 status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj); 1419 break; 1420 } 1421 out: 1422 gss_put_ctx(ctx); 1423 dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status); 1424 return status; 1425 } 1426 1427 static inline int 1428 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1429 struct rpc_rqst *rqstp, __be32 **p) 1430 { 1431 struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; 1432 struct xdr_buf integ_buf; 1433 struct xdr_netobj mic; 1434 u32 data_offset, mic_offset; 1435 u32 integ_len; 1436 u32 maj_stat; 1437 int status = -EIO; 1438 1439 integ_len = ntohl(*(*p)++); 1440 if (integ_len & 3) 1441 return status; 1442 data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base; 1443 mic_offset = integ_len + data_offset; 1444 if (mic_offset > rcv_buf->len) 1445 return status; 1446 if (ntohl(*(*p)++) != rqstp->rq_seqno) 1447 return status; 1448 1449 if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset, 1450 mic_offset - data_offset)) 1451 return status; 1452 1453 if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset)) 1454 return status; 1455 1456 maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic); 1457 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1458 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1459 if (maj_stat != GSS_S_COMPLETE) 1460 return status; 1461 return 0; 1462 } 1463 1464 static inline int 1465 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1466 struct rpc_rqst *rqstp, __be32 **p) 1467 { 1468 struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; 1469 u32 offset; 1470 u32 opaque_len; 1471 u32 maj_stat; 1472 int status = -EIO; 1473 1474 opaque_len = ntohl(*(*p)++); 1475 offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base; 1476 if (offset + opaque_len > rcv_buf->len) 1477 return status; 1478 /* remove padding: */ 1479 rcv_buf->len = offset + opaque_len; 1480 1481 maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf); 1482 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1483 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); 1484 if (maj_stat != GSS_S_COMPLETE) 1485 return status; 1486 if (ntohl(*(*p)++) != rqstp->rq_seqno) 1487 return status; 1488 1489 return 0; 1490 } 1491 1492 static int 1493 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp, 1494 __be32 *p, void *obj) 1495 { 1496 struct xdr_stream xdr; 1497 1498 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); 1499 return decode(rqstp, &xdr, obj); 1500 } 1501 1502 static int 1503 gss_unwrap_resp(struct rpc_task *task, 1504 kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj) 1505 { 1506 struct rpc_cred *cred = task->tk_rqstp->rq_cred; 1507 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 1508 gc_base); 1509 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1510 __be32 *savedp = p; 1511 struct kvec *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head; 1512 int savedlen = head->iov_len; 1513 int status = -EIO; 1514 1515 if (ctx->gc_proc != RPC_GSS_PROC_DATA) 1516 goto out_decode; 1517 switch (gss_cred->gc_service) { 1518 case RPC_GSS_SVC_NONE: 1519 break; 1520 case RPC_GSS_SVC_INTEGRITY: 1521 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p); 1522 if (status) 1523 goto out; 1524 break; 1525 case RPC_GSS_SVC_PRIVACY: 1526 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p); 1527 if (status) 1528 goto out; 1529 break; 1530 } 1531 /* take into account extra slack for integrity and privacy cases: */ 1532 cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp) 1533 + (savedlen - head->iov_len); 1534 out_decode: 1535 status = gss_unwrap_req_decode(decode, rqstp, p, obj); 1536 out: 1537 gss_put_ctx(ctx); 1538 dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid, 1539 status); 1540 return status; 1541 } 1542 1543 static const struct rpc_authops authgss_ops = { 1544 .owner = THIS_MODULE, 1545 .au_flavor = RPC_AUTH_GSS, 1546 .au_name = "RPCSEC_GSS", 1547 .create = gss_create, 1548 .destroy = gss_destroy, 1549 .lookup_cred = gss_lookup_cred, 1550 .crcreate = gss_create_cred 1551 }; 1552 1553 static const struct rpc_credops gss_credops = { 1554 .cr_name = "AUTH_GSS", 1555 .crdestroy = gss_destroy_cred, 1556 .cr_init = gss_cred_init, 1557 .crbind = rpcauth_generic_bind_cred, 1558 .crmatch = gss_match, 1559 .crmarshal = gss_marshal, 1560 .crrefresh = gss_refresh, 1561 .crvalidate = gss_validate, 1562 .crwrap_req = gss_wrap_req, 1563 .crunwrap_resp = gss_unwrap_resp, 1564 }; 1565 1566 static const struct rpc_credops gss_nullops = { 1567 .cr_name = "AUTH_GSS", 1568 .crdestroy = gss_destroy_nullcred, 1569 .crbind = rpcauth_generic_bind_cred, 1570 .crmatch = gss_match, 1571 .crmarshal = gss_marshal, 1572 .crrefresh = gss_refresh_null, 1573 .crvalidate = gss_validate, 1574 .crwrap_req = gss_wrap_req, 1575 .crunwrap_resp = gss_unwrap_resp, 1576 }; 1577 1578 static const struct rpc_pipe_ops gss_upcall_ops_v0 = { 1579 .upcall = rpc_pipe_generic_upcall, 1580 .downcall = gss_pipe_downcall, 1581 .destroy_msg = gss_pipe_destroy_msg, 1582 .open_pipe = gss_pipe_open_v0, 1583 .release_pipe = gss_pipe_release, 1584 }; 1585 1586 static const struct rpc_pipe_ops gss_upcall_ops_v1 = { 1587 .upcall = rpc_pipe_generic_upcall, 1588 .downcall = gss_pipe_downcall, 1589 .destroy_msg = gss_pipe_destroy_msg, 1590 .open_pipe = gss_pipe_open_v1, 1591 .release_pipe = gss_pipe_release, 1592 }; 1593 1594 /* 1595 * Initialize RPCSEC_GSS module 1596 */ 1597 static int __init init_rpcsec_gss(void) 1598 { 1599 int err = 0; 1600 1601 err = rpcauth_register(&authgss_ops); 1602 if (err) 1603 goto out; 1604 err = gss_svc_init(); 1605 if (err) 1606 goto out_unregister; 1607 rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version"); 1608 return 0; 1609 out_unregister: 1610 rpcauth_unregister(&authgss_ops); 1611 out: 1612 return err; 1613 } 1614 1615 static void __exit exit_rpcsec_gss(void) 1616 { 1617 gss_svc_shutdown(); 1618 rpcauth_unregister(&authgss_ops); 1619 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1620 } 1621 1622 MODULE_LICENSE("GPL"); 1623 module_param_named(expired_cred_retry_delay, 1624 gss_expired_cred_retry_delay, 1625 uint, 0644); 1626 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until " 1627 "the RPC engine retries an expired credential"); 1628 1629 module_init(init_rpcsec_gss) 1630 module_exit(exit_rpcsec_gss) 1631