auth_gss.c revision 6e84c7b66a0aa0be16a7728d1e687c57978dac2c
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 * $Id$ 38 */ 39 40 41#include <linux/module.h> 42#include <linux/init.h> 43#include <linux/types.h> 44#include <linux/slab.h> 45#include <linux/sched.h> 46#include <linux/pagemap.h> 47#include <linux/sunrpc/clnt.h> 48#include <linux/sunrpc/auth.h> 49#include <linux/sunrpc/auth_gss.h> 50#include <linux/sunrpc/svcauth_gss.h> 51#include <linux/sunrpc/gss_err.h> 52#include <linux/workqueue.h> 53#include <linux/sunrpc/rpc_pipe_fs.h> 54#include <linux/sunrpc/gss_api.h> 55#include <asm/uaccess.h> 56 57static struct rpc_authops authgss_ops; 58 59static struct rpc_credops gss_credops; 60 61#ifdef RPC_DEBUG 62# define RPCDBG_FACILITY RPCDBG_AUTH 63#endif 64 65#define NFS_NGROUPS 16 66 67#define GSS_CRED_EXPIRE (60 * HZ) /* XXX: reasonable? */ 68#define GSS_CRED_SLACK 1024 /* XXX: unused */ 69/* length of a krb5 verifier (48), plus data added before arguments when 70 * using integrity (two 4-byte integers): */ 71#define GSS_VERF_SLACK 100 72 73/* XXX this define must match the gssd define 74* as it is passed to gssd to signal the use of 75* machine creds should be part of the shared rpc interface */ 76 77#define CA_RUN_AS_MACHINE 0x00000200 78 79/* dump the buffer in `emacs-hexl' style */ 80#define isprint(c) ((c > 0x1f) && (c < 0x7f)) 81 82static DEFINE_RWLOCK(gss_ctx_lock); 83 84struct gss_auth { 85 struct rpc_auth rpc_auth; 86 struct gss_api_mech *mech; 87 enum rpc_gss_svc service; 88 struct rpc_clnt *client; 89 struct dentry *dentry; 90}; 91 92static void gss_destroy_ctx(struct gss_cl_ctx *); 93static struct rpc_pipe_ops gss_upcall_ops; 94 95static inline struct gss_cl_ctx * 96gss_get_ctx(struct gss_cl_ctx *ctx) 97{ 98 atomic_inc(&ctx->count); 99 return ctx; 100} 101 102static inline void 103gss_put_ctx(struct gss_cl_ctx *ctx) 104{ 105 if (atomic_dec_and_test(&ctx->count)) 106 gss_destroy_ctx(ctx); 107} 108 109static void 110gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx) 111{ 112 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 113 struct gss_cl_ctx *old; 114 write_lock(&gss_ctx_lock); 115 old = gss_cred->gc_ctx; 116 gss_cred->gc_ctx = ctx; 117 cred->cr_flags |= RPCAUTH_CRED_UPTODATE; 118 cred->cr_flags &= ~RPCAUTH_CRED_NEW; 119 write_unlock(&gss_ctx_lock); 120 if (old) 121 gss_put_ctx(old); 122} 123 124static int 125gss_cred_is_uptodate_ctx(struct rpc_cred *cred) 126{ 127 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 128 int res = 0; 129 130 read_lock(&gss_ctx_lock); 131 if ((cred->cr_flags & RPCAUTH_CRED_UPTODATE) && gss_cred->gc_ctx) 132 res = 1; 133 read_unlock(&gss_ctx_lock); 134 return res; 135} 136 137static const void * 138simple_get_bytes(const void *p, const void *end, void *res, size_t len) 139{ 140 const void *q = (const void *)((const char *)p + len); 141 if (unlikely(q > end || q < p)) 142 return ERR_PTR(-EFAULT); 143 memcpy(res, p, len); 144 return q; 145} 146 147static inline const void * 148simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest) 149{ 150 const void *q; 151 unsigned int len; 152 153 p = simple_get_bytes(p, end, &len, sizeof(len)); 154 if (IS_ERR(p)) 155 return p; 156 q = (const void *)((const char *)p + len); 157 if (unlikely(q > end || q < p)) 158 return ERR_PTR(-EFAULT); 159 dest->data = kmemdup(p, len, GFP_KERNEL); 160 if (unlikely(dest->data == NULL)) 161 return ERR_PTR(-ENOMEM); 162 dest->len = len; 163 return q; 164} 165 166static struct gss_cl_ctx * 167gss_cred_get_ctx(struct rpc_cred *cred) 168{ 169 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); 170 struct gss_cl_ctx *ctx = NULL; 171 172 read_lock(&gss_ctx_lock); 173 if (gss_cred->gc_ctx) 174 ctx = gss_get_ctx(gss_cred->gc_ctx); 175 read_unlock(&gss_ctx_lock); 176 return ctx; 177} 178 179static struct gss_cl_ctx * 180gss_alloc_context(void) 181{ 182 struct gss_cl_ctx *ctx; 183 184 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 185 if (ctx != NULL) { 186 ctx->gc_proc = RPC_GSS_PROC_DATA; 187 ctx->gc_seq = 1; /* NetApp 6.4R1 doesn't accept seq. no. 0 */ 188 spin_lock_init(&ctx->gc_seq_lock); 189 atomic_set(&ctx->count,1); 190 } 191 return ctx; 192} 193 194#define GSSD_MIN_TIMEOUT (60 * 60) 195static const void * 196gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm) 197{ 198 const void *q; 199 unsigned int seclen; 200 unsigned int timeout; 201 u32 window_size; 202 int ret; 203 204 /* First unsigned int gives the lifetime (in seconds) of the cred */ 205 p = simple_get_bytes(p, end, &timeout, sizeof(timeout)); 206 if (IS_ERR(p)) 207 goto err; 208 if (timeout == 0) 209 timeout = GSSD_MIN_TIMEOUT; 210 ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4; 211 /* Sequence number window. Determines the maximum number of simultaneous requests */ 212 p = simple_get_bytes(p, end, &window_size, sizeof(window_size)); 213 if (IS_ERR(p)) 214 goto err; 215 ctx->gc_win = window_size; 216 /* gssd signals an error by passing ctx->gc_win = 0: */ 217 if (ctx->gc_win == 0) { 218 /* in which case, p points to an error code which we ignore */ 219 p = 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); 236 if (ret < 0) { 237 p = ERR_PTR(ret); 238 goto err; 239 } 240 return q; 241err: 242 dprintk("RPC: gss_fill_context returning %ld\n", -PTR_ERR(p)); 243 return p; 244} 245 246 247struct gss_upcall_msg { 248 atomic_t count; 249 uid_t uid; 250 struct rpc_pipe_msg msg; 251 struct list_head list; 252 struct gss_auth *auth; 253 struct rpc_wait_queue rpc_waitqueue; 254 wait_queue_head_t waitqueue; 255 struct gss_cl_ctx *ctx; 256}; 257 258static void 259gss_release_msg(struct gss_upcall_msg *gss_msg) 260{ 261 if (!atomic_dec_and_test(&gss_msg->count)) 262 return; 263 BUG_ON(!list_empty(&gss_msg->list)); 264 if (gss_msg->ctx != NULL) 265 gss_put_ctx(gss_msg->ctx); 266 kfree(gss_msg); 267} 268 269static struct gss_upcall_msg * 270__gss_find_upcall(struct rpc_inode *rpci, uid_t uid) 271{ 272 struct gss_upcall_msg *pos; 273 list_for_each_entry(pos, &rpci->in_downcall, list) { 274 if (pos->uid != uid) 275 continue; 276 atomic_inc(&pos->count); 277 dprintk("RPC: gss_find_upcall found msg %p\n", pos); 278 return pos; 279 } 280 dprintk("RPC: gss_find_upcall found nothing\n"); 281 return NULL; 282} 283 284/* Try to add a upcall to the pipefs queue. 285 * If an upcall owned by our uid already exists, then we return a reference 286 * to that upcall instead of adding the new upcall. 287 */ 288static inline struct gss_upcall_msg * 289gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg) 290{ 291 struct inode *inode = gss_auth->dentry->d_inode; 292 struct rpc_inode *rpci = RPC_I(inode); 293 struct gss_upcall_msg *old; 294 295 spin_lock(&inode->i_lock); 296 old = __gss_find_upcall(rpci, gss_msg->uid); 297 if (old == NULL) { 298 atomic_inc(&gss_msg->count); 299 list_add(&gss_msg->list, &rpci->in_downcall); 300 } else 301 gss_msg = old; 302 spin_unlock(&inode->i_lock); 303 return gss_msg; 304} 305 306static void 307__gss_unhash_msg(struct gss_upcall_msg *gss_msg) 308{ 309 list_del_init(&gss_msg->list); 310 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno); 311 wake_up_all(&gss_msg->waitqueue); 312 atomic_dec(&gss_msg->count); 313} 314 315static void 316gss_unhash_msg(struct gss_upcall_msg *gss_msg) 317{ 318 struct gss_auth *gss_auth = gss_msg->auth; 319 struct inode *inode = gss_auth->dentry->d_inode; 320 321 if (list_empty(&gss_msg->list)) 322 return; 323 spin_lock(&inode->i_lock); 324 if (!list_empty(&gss_msg->list)) 325 __gss_unhash_msg(gss_msg); 326 spin_unlock(&inode->i_lock); 327} 328 329static void 330gss_upcall_callback(struct rpc_task *task) 331{ 332 struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred, 333 struct gss_cred, gc_base); 334 struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall; 335 struct inode *inode = gss_msg->auth->dentry->d_inode; 336 337 if (gss_msg->ctx) 338 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx)); 339 else 340 task->tk_status = gss_msg->msg.errno; 341 spin_lock(&inode->i_lock); 342 gss_cred->gc_upcall = NULL; 343 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno); 344 spin_unlock(&inode->i_lock); 345 gss_release_msg(gss_msg); 346} 347 348static inline struct gss_upcall_msg * 349gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid) 350{ 351 struct gss_upcall_msg *gss_msg; 352 353 gss_msg = kzalloc(sizeof(*gss_msg), GFP_KERNEL); 354 if (gss_msg != NULL) { 355 INIT_LIST_HEAD(&gss_msg->list); 356 rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq"); 357 init_waitqueue_head(&gss_msg->waitqueue); 358 atomic_set(&gss_msg->count, 1); 359 gss_msg->msg.data = &gss_msg->uid; 360 gss_msg->msg.len = sizeof(gss_msg->uid); 361 gss_msg->uid = uid; 362 gss_msg->auth = gss_auth; 363 } 364 return gss_msg; 365} 366 367static struct gss_upcall_msg * 368gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred) 369{ 370 struct gss_upcall_msg *gss_new, *gss_msg; 371 372 gss_new = gss_alloc_msg(gss_auth, cred->cr_uid); 373 if (gss_new == NULL) 374 return ERR_PTR(-ENOMEM); 375 gss_msg = gss_add_msg(gss_auth, gss_new); 376 if (gss_msg == gss_new) { 377 int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg); 378 if (res) { 379 gss_unhash_msg(gss_new); 380 gss_msg = ERR_PTR(res); 381 } 382 } else 383 gss_release_msg(gss_new); 384 return gss_msg; 385} 386 387static inline int 388gss_refresh_upcall(struct rpc_task *task) 389{ 390 struct rpc_cred *cred = task->tk_msg.rpc_cred; 391 struct gss_auth *gss_auth = container_of(cred->cr_auth, 392 struct gss_auth, rpc_auth); 393 struct gss_cred *gss_cred = container_of(cred, 394 struct gss_cred, gc_base); 395 struct gss_upcall_msg *gss_msg; 396 struct inode *inode = gss_auth->dentry->d_inode; 397 int err = 0; 398 399 dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid, 400 cred->cr_uid); 401 gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred); 402 if (IS_ERR(gss_msg)) { 403 err = PTR_ERR(gss_msg); 404 goto out; 405 } 406 spin_lock(&inode->i_lock); 407 if (gss_cred->gc_upcall != NULL) 408 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL); 409 else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) { 410 task->tk_timeout = 0; 411 gss_cred->gc_upcall = gss_msg; 412 /* gss_upcall_callback will release the reference to gss_upcall_msg */ 413 atomic_inc(&gss_msg->count); 414 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL); 415 } else 416 err = gss_msg->msg.errno; 417 spin_unlock(&inode->i_lock); 418 gss_release_msg(gss_msg); 419out: 420 dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n", 421 task->tk_pid, cred->cr_uid, err); 422 return err; 423} 424 425static inline int 426gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred) 427{ 428 struct inode *inode = gss_auth->dentry->d_inode; 429 struct rpc_cred *cred = &gss_cred->gc_base; 430 struct gss_upcall_msg *gss_msg; 431 DEFINE_WAIT(wait); 432 int err = 0; 433 434 dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid); 435 gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred); 436 if (IS_ERR(gss_msg)) { 437 err = PTR_ERR(gss_msg); 438 goto out; 439 } 440 for (;;) { 441 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE); 442 spin_lock(&inode->i_lock); 443 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) { 444 spin_unlock(&inode->i_lock); 445 break; 446 } 447 spin_unlock(&inode->i_lock); 448 if (signalled()) { 449 err = -ERESTARTSYS; 450 goto out_intr; 451 } 452 schedule(); 453 } 454 if (gss_msg->ctx) 455 gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx)); 456 else 457 err = gss_msg->msg.errno; 458out_intr: 459 finish_wait(&gss_msg->waitqueue, &wait); 460 gss_release_msg(gss_msg); 461out: 462 dprintk("RPC: gss_create_upcall for uid %u result %d\n", 463 cred->cr_uid, err); 464 return err; 465} 466 467static ssize_t 468gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg, 469 char __user *dst, size_t buflen) 470{ 471 char *data = (char *)msg->data + msg->copied; 472 ssize_t mlen = msg->len; 473 ssize_t left; 474 475 if (mlen > buflen) 476 mlen = buflen; 477 left = copy_to_user(dst, data, mlen); 478 if (left < 0) { 479 msg->errno = left; 480 return left; 481 } 482 mlen -= left; 483 msg->copied += mlen; 484 msg->errno = 0; 485 return mlen; 486} 487 488#define MSG_BUF_MAXSIZE 1024 489 490static ssize_t 491gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) 492{ 493 const void *p, *end; 494 void *buf; 495 struct rpc_clnt *clnt; 496 struct gss_upcall_msg *gss_msg; 497 struct inode *inode = filp->f_path.dentry->d_inode; 498 struct gss_cl_ctx *ctx; 499 uid_t uid; 500 ssize_t err = -EFBIG; 501 502 if (mlen > MSG_BUF_MAXSIZE) 503 goto out; 504 err = -ENOMEM; 505 buf = kmalloc(mlen, GFP_KERNEL); 506 if (!buf) 507 goto out; 508 509 clnt = RPC_I(inode)->private; 510 err = -EFAULT; 511 if (copy_from_user(buf, src, mlen)) 512 goto err; 513 514 end = (const void *)((char *)buf + mlen); 515 p = simple_get_bytes(buf, end, &uid, sizeof(uid)); 516 if (IS_ERR(p)) { 517 err = PTR_ERR(p); 518 goto err; 519 } 520 521 err = -ENOMEM; 522 ctx = gss_alloc_context(); 523 if (ctx == NULL) 524 goto err; 525 526 err = -ENOENT; 527 /* Find a matching upcall */ 528 spin_lock(&inode->i_lock); 529 gss_msg = __gss_find_upcall(RPC_I(inode), uid); 530 if (gss_msg == NULL) { 531 spin_unlock(&inode->i_lock); 532 goto err_put_ctx; 533 } 534 list_del_init(&gss_msg->list); 535 spin_unlock(&inode->i_lock); 536 537 p = gss_fill_context(p, end, ctx, gss_msg->auth->mech); 538 if (IS_ERR(p)) { 539 err = PTR_ERR(p); 540 gss_msg->msg.errno = (err == -EACCES) ? -EACCES : -EAGAIN; 541 goto err_release_msg; 542 } 543 gss_msg->ctx = gss_get_ctx(ctx); 544 err = mlen; 545 546err_release_msg: 547 spin_lock(&inode->i_lock); 548 __gss_unhash_msg(gss_msg); 549 spin_unlock(&inode->i_lock); 550 gss_release_msg(gss_msg); 551err_put_ctx: 552 gss_put_ctx(ctx); 553err: 554 kfree(buf); 555out: 556 dprintk("RPC: gss_pipe_downcall returning %Zd\n", err); 557 return err; 558} 559 560static void 561gss_pipe_release(struct inode *inode) 562{ 563 struct rpc_inode *rpci = RPC_I(inode); 564 struct gss_upcall_msg *gss_msg; 565 566 spin_lock(&inode->i_lock); 567 while (!list_empty(&rpci->in_downcall)) { 568 569 gss_msg = list_entry(rpci->in_downcall.next, 570 struct gss_upcall_msg, list); 571 gss_msg->msg.errno = -EPIPE; 572 atomic_inc(&gss_msg->count); 573 __gss_unhash_msg(gss_msg); 574 spin_unlock(&inode->i_lock); 575 gss_release_msg(gss_msg); 576 spin_lock(&inode->i_lock); 577 } 578 spin_unlock(&inode->i_lock); 579} 580 581static void 582gss_pipe_destroy_msg(struct rpc_pipe_msg *msg) 583{ 584 struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg); 585 static unsigned long ratelimit; 586 587 if (msg->errno < 0) { 588 dprintk("RPC: gss_pipe_destroy_msg releasing msg %p\n", 589 gss_msg); 590 atomic_inc(&gss_msg->count); 591 gss_unhash_msg(gss_msg); 592 if (msg->errno == -ETIMEDOUT) { 593 unsigned long now = jiffies; 594 if (time_after(now, ratelimit)) { 595 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n" 596 "Please check user daemon is running!\n"); 597 ratelimit = now + 15*HZ; 598 } 599 } 600 gss_release_msg(gss_msg); 601 } 602} 603 604/* 605 * NOTE: we have the opportunity to use different 606 * parameters based on the input flavor (which must be a pseudoflavor) 607 */ 608static struct rpc_auth * 609gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor) 610{ 611 struct gss_auth *gss_auth; 612 struct rpc_auth * auth; 613 int err = -ENOMEM; /* XXX? */ 614 615 dprintk("RPC: creating GSS authenticator for client %p\n", clnt); 616 617 if (!try_module_get(THIS_MODULE)) 618 return ERR_PTR(err); 619 if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL))) 620 goto out_dec; 621 gss_auth->client = clnt; 622 err = -EINVAL; 623 gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor); 624 if (!gss_auth->mech) { 625 printk(KERN_WARNING "%s: Pseudoflavor %d not found!", 626 __FUNCTION__, flavor); 627 goto err_free; 628 } 629 gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor); 630 if (gss_auth->service == 0) 631 goto err_put_mech; 632 auth = &gss_auth->rpc_auth; 633 auth->au_cslack = GSS_CRED_SLACK >> 2; 634 auth->au_rslack = GSS_VERF_SLACK >> 2; 635 auth->au_ops = &authgss_ops; 636 auth->au_flavor = flavor; 637 atomic_set(&auth->au_count, 1); 638 639 err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE); 640 if (err) 641 goto err_put_mech; 642 643 gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name, 644 clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN); 645 if (IS_ERR(gss_auth->dentry)) { 646 err = PTR_ERR(gss_auth->dentry); 647 goto err_put_mech; 648 } 649 650 return auth; 651err_put_mech: 652 gss_mech_put(gss_auth->mech); 653err_free: 654 kfree(gss_auth); 655out_dec: 656 module_put(THIS_MODULE); 657 return ERR_PTR(err); 658} 659 660static void 661gss_destroy(struct rpc_auth *auth) 662{ 663 struct gss_auth *gss_auth; 664 665 dprintk("RPC: destroying GSS authenticator %p flavor %d\n", 666 auth, auth->au_flavor); 667 668 gss_auth = container_of(auth, struct gss_auth, rpc_auth); 669 rpc_unlink(gss_auth->dentry); 670 gss_auth->dentry = NULL; 671 gss_mech_put(gss_auth->mech); 672 673 rpcauth_free_credcache(auth); 674 kfree(gss_auth); 675 module_put(THIS_MODULE); 676} 677 678/* gss_destroy_cred (and gss_destroy_ctx) are used to clean up after failure 679 * to create a new cred or context, so they check that things have been 680 * allocated before freeing them. */ 681static void 682gss_destroy_ctx(struct gss_cl_ctx *ctx) 683{ 684 dprintk("RPC: gss_destroy_ctx\n"); 685 686 if (ctx->gc_gss_ctx) 687 gss_delete_sec_context(&ctx->gc_gss_ctx); 688 689 kfree(ctx->gc_wire_ctx.data); 690 kfree(ctx); 691} 692 693static void 694gss_destroy_cred(struct rpc_cred *rc) 695{ 696 struct gss_cred *cred = container_of(rc, struct gss_cred, gc_base); 697 698 dprintk("RPC: gss_destroy_cred \n"); 699 700 if (cred->gc_ctx) 701 gss_put_ctx(cred->gc_ctx); 702 kfree(cred); 703} 704 705/* 706 * Lookup RPCSEC_GSS cred for the current process 707 */ 708static struct rpc_cred * 709gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 710{ 711 return rpcauth_lookup_credcache(auth, acred, flags); 712} 713 714static struct rpc_cred * 715gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) 716{ 717 struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); 718 struct gss_cred *cred = NULL; 719 int err = -ENOMEM; 720 721 dprintk("RPC: gss_create_cred for uid %d, flavor %d\n", 722 acred->uid, auth->au_flavor); 723 724 if (!(cred = kzalloc(sizeof(*cred), GFP_KERNEL))) 725 goto out_err; 726 727 atomic_set(&cred->gc_count, 1); 728 cred->gc_uid = acred->uid; 729 /* 730 * Note: in order to force a call to call_refresh(), we deliberately 731 * fail to flag the credential as RPCAUTH_CRED_UPTODATE. 732 */ 733 cred->gc_flags = 0; 734 cred->gc_base.cr_auth = auth; 735 cred->gc_base.cr_ops = &gss_credops; 736 cred->gc_base.cr_flags = RPCAUTH_CRED_NEW; 737 cred->gc_service = gss_auth->service; 738 return &cred->gc_base; 739 740out_err: 741 dprintk("RPC: gss_create_cred failed with error %d\n", err); 742 return ERR_PTR(err); 743} 744 745static int 746gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred) 747{ 748 struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); 749 struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base); 750 int err; 751 752 do { 753 err = gss_create_upcall(gss_auth, gss_cred); 754 } while (err == -EAGAIN); 755 return err; 756} 757 758static int 759gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags) 760{ 761 struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base); 762 763 /* 764 * If the searchflags have set RPCAUTH_LOOKUP_NEW, then 765 * we don't really care if the credential has expired or not, 766 * since the caller should be prepared to reinitialise it. 767 */ 768 if ((flags & RPCAUTH_LOOKUP_NEW) && (rc->cr_flags & RPCAUTH_CRED_NEW)) 769 goto out; 770 /* Don't match with creds that have expired. */ 771 if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry)) 772 return 0; 773out: 774 return (rc->cr_uid == acred->uid); 775} 776 777/* 778* Marshal credentials. 779* Maybe we should keep a cached credential for performance reasons. 780*/ 781static __be32 * 782gss_marshal(struct rpc_task *task, __be32 *p) 783{ 784 struct rpc_cred *cred = task->tk_msg.rpc_cred; 785 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 786 gc_base); 787 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 788 __be32 *cred_len; 789 struct rpc_rqst *req = task->tk_rqstp; 790 u32 maj_stat = 0; 791 struct xdr_netobj mic; 792 struct kvec iov; 793 struct xdr_buf verf_buf; 794 795 dprintk("RPC: %5u gss_marshal\n", task->tk_pid); 796 797 *p++ = htonl(RPC_AUTH_GSS); 798 cred_len = p++; 799 800 spin_lock(&ctx->gc_seq_lock); 801 req->rq_seqno = ctx->gc_seq++; 802 spin_unlock(&ctx->gc_seq_lock); 803 804 *p++ = htonl((u32) RPC_GSS_VERSION); 805 *p++ = htonl((u32) ctx->gc_proc); 806 *p++ = htonl((u32) req->rq_seqno); 807 *p++ = htonl((u32) gss_cred->gc_service); 808 p = xdr_encode_netobj(p, &ctx->gc_wire_ctx); 809 *cred_len = htonl((p - (cred_len + 1)) << 2); 810 811 /* We compute the checksum for the verifier over the xdr-encoded bytes 812 * starting with the xid and ending at the end of the credential: */ 813 iov.iov_base = xprt_skip_transport_header(task->tk_xprt, 814 req->rq_snd_buf.head[0].iov_base); 815 iov.iov_len = (u8 *)p - (u8 *)iov.iov_base; 816 xdr_buf_from_iov(&iov, &verf_buf); 817 818 /* set verifier flavor*/ 819 *p++ = htonl(RPC_AUTH_GSS); 820 821 mic.data = (u8 *)(p + 1); 822 maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic); 823 if (maj_stat == GSS_S_CONTEXT_EXPIRED) { 824 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE; 825 } else if (maj_stat != 0) { 826 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat); 827 goto out_put_ctx; 828 } 829 p = xdr_encode_opaque(p, NULL, mic.len); 830 gss_put_ctx(ctx); 831 return p; 832out_put_ctx: 833 gss_put_ctx(ctx); 834 return NULL; 835} 836 837/* 838* Refresh credentials. XXX - finish 839*/ 840static int 841gss_refresh(struct rpc_task *task) 842{ 843 844 if (!gss_cred_is_uptodate_ctx(task->tk_msg.rpc_cred)) 845 return gss_refresh_upcall(task); 846 return 0; 847} 848 849static __be32 * 850gss_validate(struct rpc_task *task, __be32 *p) 851{ 852 struct rpc_cred *cred = task->tk_msg.rpc_cred; 853 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 854 __be32 seq; 855 struct kvec iov; 856 struct xdr_buf verf_buf; 857 struct xdr_netobj mic; 858 u32 flav,len; 859 u32 maj_stat; 860 861 dprintk("RPC: %5u gss_validate\n", task->tk_pid); 862 863 flav = ntohl(*p++); 864 if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE) 865 goto out_bad; 866 if (flav != RPC_AUTH_GSS) 867 goto out_bad; 868 seq = htonl(task->tk_rqstp->rq_seqno); 869 iov.iov_base = &seq; 870 iov.iov_len = sizeof(seq); 871 xdr_buf_from_iov(&iov, &verf_buf); 872 mic.data = (u8 *)p; 873 mic.len = len; 874 875 maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic); 876 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 877 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE; 878 if (maj_stat) 879 goto out_bad; 880 /* We leave it to unwrap to calculate au_rslack. For now we just 881 * calculate the length of the verifier: */ 882 task->tk_auth->au_verfsize = XDR_QUADLEN(len) + 2; 883 gss_put_ctx(ctx); 884 dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n", 885 task->tk_pid); 886 return p + XDR_QUADLEN(len); 887out_bad: 888 gss_put_ctx(ctx); 889 dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid); 890 return NULL; 891} 892 893static inline int 894gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 895 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj) 896{ 897 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 898 struct xdr_buf integ_buf; 899 __be32 *integ_len = NULL; 900 struct xdr_netobj mic; 901 u32 offset; 902 __be32 *q; 903 struct kvec *iov; 904 u32 maj_stat = 0; 905 int status = -EIO; 906 907 integ_len = p++; 908 offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; 909 *p++ = htonl(rqstp->rq_seqno); 910 911 status = encode(rqstp, p, obj); 912 if (status) 913 return status; 914 915 if (xdr_buf_subsegment(snd_buf, &integ_buf, 916 offset, snd_buf->len - offset)) 917 return status; 918 *integ_len = htonl(integ_buf.len); 919 920 /* guess whether we're in the head or the tail: */ 921 if (snd_buf->page_len || snd_buf->tail[0].iov_len) 922 iov = snd_buf->tail; 923 else 924 iov = snd_buf->head; 925 p = iov->iov_base + iov->iov_len; 926 mic.data = (u8 *)(p + 1); 927 928 maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic); 929 status = -EIO; /* XXX? */ 930 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 931 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE; 932 else if (maj_stat) 933 return status; 934 q = xdr_encode_opaque(p, NULL, mic.len); 935 936 offset = (u8 *)q - (u8 *)p; 937 iov->iov_len += offset; 938 snd_buf->len += offset; 939 return 0; 940} 941 942static void 943priv_release_snd_buf(struct rpc_rqst *rqstp) 944{ 945 int i; 946 947 for (i=0; i < rqstp->rq_enc_pages_num; i++) 948 __free_page(rqstp->rq_enc_pages[i]); 949 kfree(rqstp->rq_enc_pages); 950} 951 952static int 953alloc_enc_pages(struct rpc_rqst *rqstp) 954{ 955 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 956 int first, last, i; 957 958 if (snd_buf->page_len == 0) { 959 rqstp->rq_enc_pages_num = 0; 960 return 0; 961 } 962 963 first = snd_buf->page_base >> PAGE_CACHE_SHIFT; 964 last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT; 965 rqstp->rq_enc_pages_num = last - first + 1 + 1; 966 rqstp->rq_enc_pages 967 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *), 968 GFP_NOFS); 969 if (!rqstp->rq_enc_pages) 970 goto out; 971 for (i=0; i < rqstp->rq_enc_pages_num; i++) { 972 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS); 973 if (rqstp->rq_enc_pages[i] == NULL) 974 goto out_free; 975 } 976 rqstp->rq_release_snd_buf = priv_release_snd_buf; 977 return 0; 978out_free: 979 for (i--; i >= 0; i--) { 980 __free_page(rqstp->rq_enc_pages[i]); 981 } 982out: 983 return -EAGAIN; 984} 985 986static inline int 987gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 988 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj) 989{ 990 struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; 991 u32 offset; 992 u32 maj_stat; 993 int status; 994 __be32 *opaque_len; 995 struct page **inpages; 996 int first; 997 int pad; 998 struct kvec *iov; 999 char *tmp; 1000 1001 opaque_len = p++; 1002 offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; 1003 *p++ = htonl(rqstp->rq_seqno); 1004 1005 status = encode(rqstp, p, obj); 1006 if (status) 1007 return status; 1008 1009 status = alloc_enc_pages(rqstp); 1010 if (status) 1011 return status; 1012 first = snd_buf->page_base >> PAGE_CACHE_SHIFT; 1013 inpages = snd_buf->pages + first; 1014 snd_buf->pages = rqstp->rq_enc_pages; 1015 snd_buf->page_base -= first << PAGE_CACHE_SHIFT; 1016 /* Give the tail its own page, in case we need extra space in the 1017 * head when wrapping: */ 1018 if (snd_buf->page_len || snd_buf->tail[0].iov_len) { 1019 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]); 1020 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len); 1021 snd_buf->tail[0].iov_base = tmp; 1022 } 1023 maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages); 1024 /* RPC_SLACK_SPACE should prevent this ever happening: */ 1025 BUG_ON(snd_buf->len > snd_buf->buflen); 1026 status = -EIO; 1027 /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was 1028 * done anyway, so it's safe to put the request on the wire: */ 1029 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1030 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE; 1031 else if (maj_stat) 1032 return status; 1033 1034 *opaque_len = htonl(snd_buf->len - offset); 1035 /* guess whether we're in the head or the tail: */ 1036 if (snd_buf->page_len || snd_buf->tail[0].iov_len) 1037 iov = snd_buf->tail; 1038 else 1039 iov = snd_buf->head; 1040 p = iov->iov_base + iov->iov_len; 1041 pad = 3 - ((snd_buf->len - offset - 1) & 3); 1042 memset(p, 0, pad); 1043 iov->iov_len += pad; 1044 snd_buf->len += pad; 1045 1046 return 0; 1047} 1048 1049static int 1050gss_wrap_req(struct rpc_task *task, 1051 kxdrproc_t encode, void *rqstp, __be32 *p, void *obj) 1052{ 1053 struct rpc_cred *cred = task->tk_msg.rpc_cred; 1054 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 1055 gc_base); 1056 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1057 int status = -EIO; 1058 1059 dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid); 1060 if (ctx->gc_proc != RPC_GSS_PROC_DATA) { 1061 /* The spec seems a little ambiguous here, but I think that not 1062 * wrapping context destruction requests makes the most sense. 1063 */ 1064 status = encode(rqstp, p, obj); 1065 goto out; 1066 } 1067 switch (gss_cred->gc_service) { 1068 case RPC_GSS_SVC_NONE: 1069 status = encode(rqstp, p, obj); 1070 break; 1071 case RPC_GSS_SVC_INTEGRITY: 1072 status = gss_wrap_req_integ(cred, ctx, encode, 1073 rqstp, p, obj); 1074 break; 1075 case RPC_GSS_SVC_PRIVACY: 1076 status = gss_wrap_req_priv(cred, ctx, encode, 1077 rqstp, p, obj); 1078 break; 1079 } 1080out: 1081 gss_put_ctx(ctx); 1082 dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status); 1083 return status; 1084} 1085 1086static inline int 1087gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1088 struct rpc_rqst *rqstp, __be32 **p) 1089{ 1090 struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; 1091 struct xdr_buf integ_buf; 1092 struct xdr_netobj mic; 1093 u32 data_offset, mic_offset; 1094 u32 integ_len; 1095 u32 maj_stat; 1096 int status = -EIO; 1097 1098 integ_len = ntohl(*(*p)++); 1099 if (integ_len & 3) 1100 return status; 1101 data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base; 1102 mic_offset = integ_len + data_offset; 1103 if (mic_offset > rcv_buf->len) 1104 return status; 1105 if (ntohl(*(*p)++) != rqstp->rq_seqno) 1106 return status; 1107 1108 if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset, 1109 mic_offset - data_offset)) 1110 return status; 1111 1112 if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset)) 1113 return status; 1114 1115 maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic); 1116 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1117 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE; 1118 if (maj_stat != GSS_S_COMPLETE) 1119 return status; 1120 return 0; 1121} 1122 1123static inline int 1124gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, 1125 struct rpc_rqst *rqstp, __be32 **p) 1126{ 1127 struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; 1128 u32 offset; 1129 u32 opaque_len; 1130 u32 maj_stat; 1131 int status = -EIO; 1132 1133 opaque_len = ntohl(*(*p)++); 1134 offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base; 1135 if (offset + opaque_len > rcv_buf->len) 1136 return status; 1137 /* remove padding: */ 1138 rcv_buf->len = offset + opaque_len; 1139 1140 maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf); 1141 if (maj_stat == GSS_S_CONTEXT_EXPIRED) 1142 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE; 1143 if (maj_stat != GSS_S_COMPLETE) 1144 return status; 1145 if (ntohl(*(*p)++) != rqstp->rq_seqno) 1146 return status; 1147 1148 return 0; 1149} 1150 1151 1152static int 1153gss_unwrap_resp(struct rpc_task *task, 1154 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj) 1155{ 1156 struct rpc_cred *cred = task->tk_msg.rpc_cred; 1157 struct gss_cred *gss_cred = container_of(cred, struct gss_cred, 1158 gc_base); 1159 struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); 1160 __be32 *savedp = p; 1161 struct kvec *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head; 1162 int savedlen = head->iov_len; 1163 int status = -EIO; 1164 1165 if (ctx->gc_proc != RPC_GSS_PROC_DATA) 1166 goto out_decode; 1167 switch (gss_cred->gc_service) { 1168 case RPC_GSS_SVC_NONE: 1169 break; 1170 case RPC_GSS_SVC_INTEGRITY: 1171 status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p); 1172 if (status) 1173 goto out; 1174 break; 1175 case RPC_GSS_SVC_PRIVACY: 1176 status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p); 1177 if (status) 1178 goto out; 1179 break; 1180 } 1181 /* take into account extra slack for integrity and privacy cases: */ 1182 task->tk_auth->au_rslack = task->tk_auth->au_verfsize + (p - savedp) 1183 + (savedlen - head->iov_len); 1184out_decode: 1185 status = decode(rqstp, p, obj); 1186out: 1187 gss_put_ctx(ctx); 1188 dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid, 1189 status); 1190 return status; 1191} 1192 1193static struct rpc_authops authgss_ops = { 1194 .owner = THIS_MODULE, 1195 .au_flavor = RPC_AUTH_GSS, 1196#ifdef RPC_DEBUG 1197 .au_name = "RPCSEC_GSS", 1198#endif 1199 .create = gss_create, 1200 .destroy = gss_destroy, 1201 .lookup_cred = gss_lookup_cred, 1202 .crcreate = gss_create_cred 1203}; 1204 1205static struct rpc_credops gss_credops = { 1206 .cr_name = "AUTH_GSS", 1207 .crdestroy = gss_destroy_cred, 1208 .cr_init = gss_cred_init, 1209 .crmatch = gss_match, 1210 .crmarshal = gss_marshal, 1211 .crrefresh = gss_refresh, 1212 .crvalidate = gss_validate, 1213 .crwrap_req = gss_wrap_req, 1214 .crunwrap_resp = gss_unwrap_resp, 1215}; 1216 1217static struct rpc_pipe_ops gss_upcall_ops = { 1218 .upcall = gss_pipe_upcall, 1219 .downcall = gss_pipe_downcall, 1220 .destroy_msg = gss_pipe_destroy_msg, 1221 .release_pipe = gss_pipe_release, 1222}; 1223 1224/* 1225 * Initialize RPCSEC_GSS module 1226 */ 1227static int __init init_rpcsec_gss(void) 1228{ 1229 int err = 0; 1230 1231 err = rpcauth_register(&authgss_ops); 1232 if (err) 1233 goto out; 1234 err = gss_svc_init(); 1235 if (err) 1236 goto out_unregister; 1237 return 0; 1238out_unregister: 1239 rpcauth_unregister(&authgss_ops); 1240out: 1241 return err; 1242} 1243 1244static void __exit exit_rpcsec_gss(void) 1245{ 1246 gss_svc_shutdown(); 1247 rpcauth_unregister(&authgss_ops); 1248} 1249 1250MODULE_LICENSE("GPL"); 1251module_init(init_rpcsec_gss) 1252module_exit(exit_rpcsec_gss) 1253