1 /* 2 * Neil Brown <neilb@cse.unsw.edu.au> 3 * J. Bruce Fields <bfields@umich.edu> 4 * Andy Adamson <andros@umich.edu> 5 * Dug Song <dugsong@monkey.org> 6 * 7 * RPCSEC_GSS server authentication. 8 * This implements RPCSEC_GSS as defined in rfc2203 (rpcsec_gss) and rfc2078 9 * (gssapi) 10 * 11 * The RPCSEC_GSS involves three stages: 12 * 1/ context creation 13 * 2/ data exchange 14 * 3/ context destruction 15 * 16 * Context creation is handled largely by upcalls to user-space. 17 * In particular, GSS_Accept_sec_context is handled by an upcall 18 * Data exchange is handled entirely within the kernel 19 * In particular, GSS_GetMIC, GSS_VerifyMIC, GSS_Seal, GSS_Unseal are in-kernel. 20 * Context destruction is handled in-kernel 21 * GSS_Delete_sec_context is in-kernel 22 * 23 * Context creation is initiated by a RPCSEC_GSS_INIT request arriving. 24 * The context handle and gss_token are used as a key into the rpcsec_init cache. 25 * The content of this cache includes some of the outputs of GSS_Accept_sec_context, 26 * being major_status, minor_status, context_handle, reply_token. 27 * These are sent back to the client. 28 * Sequence window management is handled by the kernel. The window size if currently 29 * a compile time constant. 30 * 31 * When user-space is happy that a context is established, it places an entry 32 * in the rpcsec_context cache. The key for this cache is the context_handle. 33 * The content includes: 34 * uid/gidlist - for determining access rights 35 * mechanism type 36 * mechanism specific information, such as a key 37 * 38 */ 39 40 #include <linux/types.h> 41 #include <linux/module.h> 42 #include <linux/pagemap.h> 43 44 #include <linux/sunrpc/auth_gss.h> 45 #include <linux/sunrpc/svcauth.h> 46 #include <linux/sunrpc/gss_err.h> 47 #include <linux/sunrpc/svcauth.h> 48 #include <linux/sunrpc/svcauth_gss.h> 49 #include <linux/sunrpc/cache.h> 50 51 #ifdef RPC_DEBUG 52 # define RPCDBG_FACILITY RPCDBG_AUTH 53 #endif 54 55 /* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests 56 * into replies. 57 * 58 * Key is context handle (\x if empty) and gss_token. 59 * Content is major_status minor_status (integers) context_handle, reply_token. 60 * 61 */ 62 63 static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b) 64 { 65 return a->len == b->len && 0 == memcmp(a->data, b->data, a->len); 66 } 67 68 #define RSI_HASHBITS 6 69 #define RSI_HASHMAX (1<<RSI_HASHBITS) 70 #define RSI_HASHMASK (RSI_HASHMAX-1) 71 72 struct rsi { 73 struct cache_head h; 74 struct xdr_netobj in_handle, in_token; 75 struct xdr_netobj out_handle, out_token; 76 int major_status, minor_status; 77 }; 78 79 static struct cache_head *rsi_table[RSI_HASHMAX]; 80 static struct cache_detail rsi_cache; 81 static struct rsi *rsi_update(struct rsi *new, struct rsi *old); 82 static struct rsi *rsi_lookup(struct rsi *item); 83 84 static void rsi_free(struct rsi *rsii) 85 { 86 kfree(rsii->in_handle.data); 87 kfree(rsii->in_token.data); 88 kfree(rsii->out_handle.data); 89 kfree(rsii->out_token.data); 90 } 91 92 static void rsi_put(struct cache_head *item, struct cache_detail *cd) 93 { 94 struct rsi *rsii = container_of(item, struct rsi, h); 95 if (cache_put(item, cd)) { 96 rsi_free(rsii); 97 kfree(rsii); 98 } 99 } 100 101 static inline int rsi_hash(struct rsi *item) 102 { 103 return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS) 104 ^ hash_mem(item->in_token.data, item->in_token.len, RSI_HASHBITS); 105 } 106 107 static int rsi_match(struct cache_head *a, struct cache_head *b) 108 { 109 struct rsi *item = container_of(a, struct rsi, h); 110 struct rsi *tmp = container_of(b, struct rsi, h); 111 return netobj_equal(&item->in_handle, &tmp->in_handle) 112 && netobj_equal(&item->in_token, &tmp->in_token); 113 } 114 115 static int dup_to_netobj(struct xdr_netobj *dst, char *src, int len) 116 { 117 dst->len = len; 118 dst->data = (len ? kmalloc(len, GFP_KERNEL) : NULL); 119 if (dst->data) 120 memcpy(dst->data, src, len); 121 if (len && !dst->data) 122 return -ENOMEM; 123 return 0; 124 } 125 126 static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src) 127 { 128 return dup_to_netobj(dst, src->data, src->len); 129 } 130 131 static void rsi_init(struct cache_head *cnew, struct cache_head *citem) 132 { 133 struct rsi *new = container_of(cnew, struct rsi, h); 134 struct rsi *item = container_of(citem, struct rsi, h); 135 136 new->out_handle.data = NULL; 137 new->out_handle.len = 0; 138 new->out_token.data = NULL; 139 new->out_token.len = 0; 140 new->in_handle.len = item->in_handle.len; 141 item->in_handle.len = 0; 142 new->in_token.len = item->in_token.len; 143 item->in_token.len = 0; 144 new->in_handle.data = item->in_handle.data; 145 item->in_handle.data = NULL; 146 new->in_token.data = item->in_token.data; 147 item->in_token.data = NULL; 148 } 149 150 static void update_rsi(struct cache_head *cnew, struct cache_head *citem) 151 { 152 struct rsi *new = container_of(cnew, struct rsi, h); 153 struct rsi *item = container_of(citem, struct rsi, h); 154 155 BUG_ON(new->out_handle.data || new->out_token.data); 156 new->out_handle.len = item->out_handle.len; 157 item->out_handle.len = 0; 158 new->out_token.len = item->out_token.len; 159 item->out_token.len = 0; 160 new->out_handle.data = item->out_handle.data; 161 item->out_handle.data = NULL; 162 new->out_token.data = item->out_token.data; 163 item->out_token.data = NULL; 164 165 new->major_status = item->major_status; 166 new->minor_status = item->minor_status; 167 } 168 169 static struct cache_head *rsi_alloc(void) 170 { 171 struct rsi *rsii = kmalloc(sizeof(*rsii), GFP_KERNEL); 172 if (rsii) 173 return &rsii->h; 174 else 175 return NULL; 176 } 177 178 static void rsi_request(struct cache_detail *cd, 179 struct cache_head *h, 180 char **bpp, int *blen) 181 { 182 struct rsi *rsii = container_of(h, struct rsi, h); 183 184 qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len); 185 qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len); 186 (*bpp)[-1] = '\n'; 187 } 188 189 190 static int rsi_parse(struct cache_detail *cd, 191 char *mesg, int mlen) 192 { 193 /* context token expiry major minor context token */ 194 char *buf = mesg; 195 char *ep; 196 int len; 197 struct rsi rsii, *rsip = NULL; 198 time_t expiry; 199 int status = -EINVAL; 200 201 memset(&rsii, 0, sizeof(rsii)); 202 /* handle */ 203 len = qword_get(&mesg, buf, mlen); 204 if (len < 0) 205 goto out; 206 status = -ENOMEM; 207 if (dup_to_netobj(&rsii.in_handle, buf, len)) 208 goto out; 209 210 /* token */ 211 len = qword_get(&mesg, buf, mlen); 212 status = -EINVAL; 213 if (len < 0) 214 goto out; 215 status = -ENOMEM; 216 if (dup_to_netobj(&rsii.in_token, buf, len)) 217 goto out; 218 219 rsip = rsi_lookup(&rsii); 220 if (!rsip) 221 goto out; 222 223 rsii.h.flags = 0; 224 /* expiry */ 225 expiry = get_expiry(&mesg); 226 status = -EINVAL; 227 if (expiry == 0) 228 goto out; 229 230 /* major/minor */ 231 len = qword_get(&mesg, buf, mlen); 232 if (len < 0) 233 goto out; 234 if (len == 0) { 235 goto out; 236 } else { 237 rsii.major_status = simple_strtoul(buf, &ep, 10); 238 if (*ep) 239 goto out; 240 len = qword_get(&mesg, buf, mlen); 241 if (len <= 0) 242 goto out; 243 rsii.minor_status = simple_strtoul(buf, &ep, 10); 244 if (*ep) 245 goto out; 246 247 /* out_handle */ 248 len = qword_get(&mesg, buf, mlen); 249 if (len < 0) 250 goto out; 251 status = -ENOMEM; 252 if (dup_to_netobj(&rsii.out_handle, buf, len)) 253 goto out; 254 255 /* out_token */ 256 len = qword_get(&mesg, buf, mlen); 257 status = -EINVAL; 258 if (len < 0) 259 goto out; 260 status = -ENOMEM; 261 if (dup_to_netobj(&rsii.out_token, buf, len)) 262 goto out; 263 } 264 rsii.h.expiry_time = expiry; 265 rsip = rsi_update(&rsii, rsip); 266 status = 0; 267 out: 268 rsi_free(&rsii); 269 if (rsip) 270 rsi_put(&rsip->h, &rsi_cache); 271 else 272 status = -ENOMEM; 273 return status; 274 } 275 276 static struct cache_detail rsi_cache = { 277 .owner = THIS_MODULE, 278 .hash_size = RSI_HASHMAX, 279 .hash_table = rsi_table, 280 .name = "auth.rpcsec.init", 281 .cache_put = rsi_put, 282 .cache_request = rsi_request, 283 .cache_parse = rsi_parse, 284 .match = rsi_match, 285 .init = rsi_init, 286 .update = update_rsi, 287 .alloc = rsi_alloc, 288 }; 289 290 static struct rsi *rsi_lookup(struct rsi *item) 291 { 292 struct cache_head *ch; 293 int hash = rsi_hash(item); 294 295 ch = sunrpc_cache_lookup(&rsi_cache, &item->h, hash); 296 if (ch) 297 return container_of(ch, struct rsi, h); 298 else 299 return NULL; 300 } 301 302 static struct rsi *rsi_update(struct rsi *new, struct rsi *old) 303 { 304 struct cache_head *ch; 305 int hash = rsi_hash(new); 306 307 ch = sunrpc_cache_update(&rsi_cache, &new->h, 308 &old->h, hash); 309 if (ch) 310 return container_of(ch, struct rsi, h); 311 else 312 return NULL; 313 } 314 315 316 /* 317 * The rpcsec_context cache is used to store a context that is 318 * used in data exchange. 319 * The key is a context handle. The content is: 320 * uid, gidlist, mechanism, service-set, mech-specific-data 321 */ 322 323 #define RSC_HASHBITS 10 324 #define RSC_HASHMAX (1<<RSC_HASHBITS) 325 #define RSC_HASHMASK (RSC_HASHMAX-1) 326 327 #define GSS_SEQ_WIN 128 328 329 struct gss_svc_seq_data { 330 /* highest seq number seen so far: */ 331 int sd_max; 332 /* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of 333 * sd_win is nonzero iff sequence number i has been seen already: */ 334 unsigned long sd_win[GSS_SEQ_WIN/BITS_PER_LONG]; 335 spinlock_t sd_lock; 336 }; 337 338 struct rsc { 339 struct cache_head h; 340 struct xdr_netobj handle; 341 struct svc_cred cred; 342 struct gss_svc_seq_data seqdata; 343 struct gss_ctx *mechctx; 344 }; 345 346 static struct cache_head *rsc_table[RSC_HASHMAX]; 347 static struct cache_detail rsc_cache; 348 static struct rsc *rsc_update(struct rsc *new, struct rsc *old); 349 static struct rsc *rsc_lookup(struct rsc *item); 350 351 static void rsc_free(struct rsc *rsci) 352 { 353 kfree(rsci->handle.data); 354 if (rsci->mechctx) 355 gss_delete_sec_context(&rsci->mechctx); 356 if (rsci->cred.cr_group_info) 357 put_group_info(rsci->cred.cr_group_info); 358 } 359 360 static void rsc_put(struct cache_head *item, struct cache_detail *cd) 361 { 362 struct rsc *rsci = container_of(item, struct rsc, h); 363 364 if (cache_put(item, cd)) { 365 rsc_free(rsci); 366 kfree(rsci); 367 } 368 } 369 370 static inline int 371 rsc_hash(struct rsc *rsci) 372 { 373 return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS); 374 } 375 376 static int 377 rsc_match(struct cache_head *a, struct cache_head *b) 378 { 379 struct rsc *new = container_of(a, struct rsc, h); 380 struct rsc *tmp = container_of(b, struct rsc, h); 381 382 return netobj_equal(&new->handle, &tmp->handle); 383 } 384 385 static void 386 rsc_init(struct cache_head *cnew, struct cache_head *ctmp) 387 { 388 struct rsc *new = container_of(cnew, struct rsc, h); 389 struct rsc *tmp = container_of(ctmp, struct rsc, h); 390 391 new->handle.len = tmp->handle.len; 392 tmp->handle.len = 0; 393 new->handle.data = tmp->handle.data; 394 tmp->handle.data = NULL; 395 new->mechctx = NULL; 396 new->cred.cr_group_info = NULL; 397 } 398 399 static void 400 update_rsc(struct cache_head *cnew, struct cache_head *ctmp) 401 { 402 struct rsc *new = container_of(cnew, struct rsc, h); 403 struct rsc *tmp = container_of(ctmp, struct rsc, h); 404 405 new->mechctx = tmp->mechctx; 406 tmp->mechctx = NULL; 407 memset(&new->seqdata, 0, sizeof(new->seqdata)); 408 spin_lock_init(&new->seqdata.sd_lock); 409 new->cred = tmp->cred; 410 tmp->cred.cr_group_info = NULL; 411 } 412 413 static struct cache_head * 414 rsc_alloc(void) 415 { 416 struct rsc *rsci = kmalloc(sizeof(*rsci), GFP_KERNEL); 417 if (rsci) 418 return &rsci->h; 419 else 420 return NULL; 421 } 422 423 static int rsc_parse(struct cache_detail *cd, 424 char *mesg, int mlen) 425 { 426 /* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */ 427 char *buf = mesg; 428 int len, rv; 429 struct rsc rsci, *rscp = NULL; 430 time_t expiry; 431 int status = -EINVAL; 432 433 memset(&rsci, 0, sizeof(rsci)); 434 /* context handle */ 435 len = qword_get(&mesg, buf, mlen); 436 if (len < 0) goto out; 437 status = -ENOMEM; 438 if (dup_to_netobj(&rsci.handle, buf, len)) 439 goto out; 440 441 rsci.h.flags = 0; 442 /* expiry */ 443 expiry = get_expiry(&mesg); 444 status = -EINVAL; 445 if (expiry == 0) 446 goto out; 447 448 rscp = rsc_lookup(&rsci); 449 if (!rscp) 450 goto out; 451 452 /* uid, or NEGATIVE */ 453 rv = get_int(&mesg, &rsci.cred.cr_uid); 454 if (rv == -EINVAL) 455 goto out; 456 if (rv == -ENOENT) 457 set_bit(CACHE_NEGATIVE, &rsci.h.flags); 458 else { 459 int N, i; 460 struct gss_api_mech *gm; 461 462 /* gid */ 463 if (get_int(&mesg, &rsci.cred.cr_gid)) 464 goto out; 465 466 /* number of additional gid's */ 467 if (get_int(&mesg, &N)) 468 goto out; 469 status = -ENOMEM; 470 rsci.cred.cr_group_info = groups_alloc(N); 471 if (rsci.cred.cr_group_info == NULL) 472 goto out; 473 474 /* gid's */ 475 status = -EINVAL; 476 for (i=0; i<N; i++) { 477 gid_t gid; 478 if (get_int(&mesg, &gid)) 479 goto out; 480 GROUP_AT(rsci.cred.cr_group_info, i) = gid; 481 } 482 483 /* mech name */ 484 len = qword_get(&mesg, buf, mlen); 485 if (len < 0) 486 goto out; 487 gm = gss_mech_get_by_name(buf); 488 status = -EOPNOTSUPP; 489 if (!gm) 490 goto out; 491 492 status = -EINVAL; 493 /* mech-specific data: */ 494 len = qword_get(&mesg, buf, mlen); 495 if (len < 0) { 496 gss_mech_put(gm); 497 goto out; 498 } 499 status = gss_import_sec_context(buf, len, gm, &rsci.mechctx); 500 if (status) { 501 gss_mech_put(gm); 502 goto out; 503 } 504 gss_mech_put(gm); 505 } 506 rsci.h.expiry_time = expiry; 507 rscp = rsc_update(&rsci, rscp); 508 status = 0; 509 out: 510 rsc_free(&rsci); 511 if (rscp) 512 rsc_put(&rscp->h, &rsc_cache); 513 else 514 status = -ENOMEM; 515 return status; 516 } 517 518 static struct cache_detail rsc_cache = { 519 .owner = THIS_MODULE, 520 .hash_size = RSC_HASHMAX, 521 .hash_table = rsc_table, 522 .name = "auth.rpcsec.context", 523 .cache_put = rsc_put, 524 .cache_parse = rsc_parse, 525 .match = rsc_match, 526 .init = rsc_init, 527 .update = update_rsc, 528 .alloc = rsc_alloc, 529 }; 530 531 static struct rsc *rsc_lookup(struct rsc *item) 532 { 533 struct cache_head *ch; 534 int hash = rsc_hash(item); 535 536 ch = sunrpc_cache_lookup(&rsc_cache, &item->h, hash); 537 if (ch) 538 return container_of(ch, struct rsc, h); 539 else 540 return NULL; 541 } 542 543 static struct rsc *rsc_update(struct rsc *new, struct rsc *old) 544 { 545 struct cache_head *ch; 546 int hash = rsc_hash(new); 547 548 ch = sunrpc_cache_update(&rsc_cache, &new->h, 549 &old->h, hash); 550 if (ch) 551 return container_of(ch, struct rsc, h); 552 else 553 return NULL; 554 } 555 556 557 static struct rsc * 558 gss_svc_searchbyctx(struct xdr_netobj *handle) 559 { 560 struct rsc rsci; 561 struct rsc *found; 562 563 memset(&rsci, 0, sizeof(rsci)); 564 if (dup_to_netobj(&rsci.handle, handle->data, handle->len)) 565 return NULL; 566 found = rsc_lookup(&rsci); 567 rsc_free(&rsci); 568 if (!found) 569 return NULL; 570 if (cache_check(&rsc_cache, &found->h, NULL)) 571 return NULL; 572 return found; 573 } 574 575 /* Implements sequence number algorithm as specified in RFC 2203. */ 576 static int 577 gss_check_seq_num(struct rsc *rsci, int seq_num) 578 { 579 struct gss_svc_seq_data *sd = &rsci->seqdata; 580 581 spin_lock(&sd->sd_lock); 582 if (seq_num > sd->sd_max) { 583 if (seq_num >= sd->sd_max + GSS_SEQ_WIN) { 584 memset(sd->sd_win,0,sizeof(sd->sd_win)); 585 sd->sd_max = seq_num; 586 } else while (sd->sd_max < seq_num) { 587 sd->sd_max++; 588 __clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win); 589 } 590 __set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win); 591 goto ok; 592 } else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) { 593 goto drop; 594 } 595 /* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */ 596 if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win)) 597 goto drop; 598 ok: 599 spin_unlock(&sd->sd_lock); 600 return 1; 601 drop: 602 spin_unlock(&sd->sd_lock); 603 return 0; 604 } 605 606 static inline u32 round_up_to_quad(u32 i) 607 { 608 return (i + 3 ) & ~3; 609 } 610 611 static inline int 612 svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o) 613 { 614 int l; 615 616 if (argv->iov_len < 4) 617 return -1; 618 o->len = ntohl(svc_getu32(argv)); 619 l = round_up_to_quad(o->len); 620 if (argv->iov_len < l) 621 return -1; 622 o->data = argv->iov_base; 623 argv->iov_base += l; 624 argv->iov_len -= l; 625 return 0; 626 } 627 628 static inline int 629 svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o) 630 { 631 u32 *p; 632 633 if (resv->iov_len + 4 > PAGE_SIZE) 634 return -1; 635 svc_putu32(resv, htonl(o->len)); 636 p = resv->iov_base + resv->iov_len; 637 resv->iov_len += round_up_to_quad(o->len); 638 if (resv->iov_len > PAGE_SIZE) 639 return -1; 640 memcpy(p, o->data, o->len); 641 memset((u8 *)p + o->len, 0, round_up_to_quad(o->len) - o->len); 642 return 0; 643 } 644 645 /* Verify the checksum on the header and return SVC_OK on success. 646 * Otherwise, return SVC_DROP (in the case of a bad sequence number) 647 * or return SVC_DENIED and indicate error in authp. 648 */ 649 static int 650 gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci, 651 u32 *rpcstart, struct rpc_gss_wire_cred *gc, u32 *authp) 652 { 653 struct gss_ctx *ctx_id = rsci->mechctx; 654 struct xdr_buf rpchdr; 655 struct xdr_netobj checksum; 656 u32 flavor = 0; 657 struct kvec *argv = &rqstp->rq_arg.head[0]; 658 struct kvec iov; 659 660 /* data to compute the checksum over: */ 661 iov.iov_base = rpcstart; 662 iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart; 663 xdr_buf_from_iov(&iov, &rpchdr); 664 665 *authp = rpc_autherr_badverf; 666 if (argv->iov_len < 4) 667 return SVC_DENIED; 668 flavor = ntohl(svc_getu32(argv)); 669 if (flavor != RPC_AUTH_GSS) 670 return SVC_DENIED; 671 if (svc_safe_getnetobj(argv, &checksum)) 672 return SVC_DENIED; 673 674 if (rqstp->rq_deferred) /* skip verification of revisited request */ 675 return SVC_OK; 676 if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) { 677 *authp = rpcsec_gsserr_credproblem; 678 return SVC_DENIED; 679 } 680 681 if (gc->gc_seq > MAXSEQ) { 682 dprintk("RPC: svcauth_gss: discarding request with large sequence number %d\n", 683 gc->gc_seq); 684 *authp = rpcsec_gsserr_ctxproblem; 685 return SVC_DENIED; 686 } 687 if (!gss_check_seq_num(rsci, gc->gc_seq)) { 688 dprintk("RPC: svcauth_gss: discarding request with old sequence number %d\n", 689 gc->gc_seq); 690 return SVC_DROP; 691 } 692 return SVC_OK; 693 } 694 695 static int 696 gss_write_null_verf(struct svc_rqst *rqstp) 697 { 698 u32 *p; 699 700 svc_putu32(rqstp->rq_res.head, htonl(RPC_AUTH_NULL)); 701 p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len; 702 /* don't really need to check if head->iov_len > PAGE_SIZE ... */ 703 *p++ = 0; 704 if (!xdr_ressize_check(rqstp, p)) 705 return -1; 706 return 0; 707 } 708 709 static int 710 gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq) 711 { 712 u32 xdr_seq; 713 u32 maj_stat; 714 struct xdr_buf verf_data; 715 struct xdr_netobj mic; 716 u32 *p; 717 struct kvec iov; 718 719 svc_putu32(rqstp->rq_res.head, htonl(RPC_AUTH_GSS)); 720 xdr_seq = htonl(seq); 721 722 iov.iov_base = &xdr_seq; 723 iov.iov_len = sizeof(xdr_seq); 724 xdr_buf_from_iov(&iov, &verf_data); 725 p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len; 726 mic.data = (u8 *)(p + 1); 727 maj_stat = gss_get_mic(ctx_id, &verf_data, &mic); 728 if (maj_stat != GSS_S_COMPLETE) 729 return -1; 730 *p++ = htonl(mic.len); 731 memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len); 732 p += XDR_QUADLEN(mic.len); 733 if (!xdr_ressize_check(rqstp, p)) 734 return -1; 735 return 0; 736 } 737 738 struct gss_domain { 739 struct auth_domain h; 740 u32 pseudoflavor; 741 }; 742 743 static struct auth_domain * 744 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc) 745 { 746 char *name; 747 748 name = gss_service_to_auth_domain_name(ctx->mech_type, svc); 749 if (!name) 750 return NULL; 751 return auth_domain_find(name); 752 } 753 754 static struct auth_ops svcauthops_gss; 755 756 int 757 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name) 758 { 759 struct gss_domain *new; 760 struct auth_domain *test; 761 int stat = -ENOMEM; 762 763 new = kmalloc(sizeof(*new), GFP_KERNEL); 764 if (!new) 765 goto out; 766 kref_init(&new->h.ref); 767 new->h.name = kmalloc(strlen(name) + 1, GFP_KERNEL); 768 if (!new->h.name) 769 goto out_free_dom; 770 strcpy(new->h.name, name); 771 new->h.flavour = &svcauthops_gss; 772 new->pseudoflavor = pseudoflavor; 773 774 test = auth_domain_lookup(name, &new->h); 775 if (test != &new->h) { /* XXX Duplicate registration? */ 776 auth_domain_put(&new->h); 777 /* dangling ref-count... */ 778 goto out; 779 } 780 return 0; 781 782 out_free_dom: 783 kfree(new); 784 out: 785 return stat; 786 } 787 788 EXPORT_SYMBOL(svcauth_gss_register_pseudoflavor); 789 790 static inline int 791 read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj) 792 { 793 u32 raw; 794 int status; 795 796 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); 797 if (status) 798 return status; 799 *obj = ntohl(raw); 800 return 0; 801 } 802 803 /* It would be nice if this bit of code could be shared with the client. 804 * Obstacles: 805 * The client shouldn't malloc(), would have to pass in own memory. 806 * The server uses base of head iovec as read pointer, while the 807 * client uses separate pointer. */ 808 static int 809 unwrap_integ_data(struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx) 810 { 811 int stat = -EINVAL; 812 u32 integ_len, maj_stat; 813 struct xdr_netobj mic; 814 struct xdr_buf integ_buf; 815 816 integ_len = ntohl(svc_getu32(&buf->head[0])); 817 if (integ_len & 3) 818 goto out; 819 if (integ_len > buf->len) 820 goto out; 821 if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len)) 822 BUG(); 823 /* copy out mic... */ 824 if (read_u32_from_xdr_buf(buf, integ_len, &mic.len)) 825 BUG(); 826 if (mic.len > RPC_MAX_AUTH_SIZE) 827 goto out; 828 mic.data = kmalloc(mic.len, GFP_KERNEL); 829 if (!mic.data) 830 goto out; 831 if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len)) 832 goto out; 833 maj_stat = gss_verify_mic(ctx, &integ_buf, &mic); 834 if (maj_stat != GSS_S_COMPLETE) 835 goto out; 836 if (ntohl(svc_getu32(&buf->head[0])) != seq) 837 goto out; 838 stat = 0; 839 out: 840 return stat; 841 } 842 843 struct gss_svc_data { 844 /* decoded gss client cred: */ 845 struct rpc_gss_wire_cred clcred; 846 /* pointer to the beginning of the procedure-specific results, 847 * which may be encrypted/checksummed in svcauth_gss_release: */ 848 u32 *body_start; 849 struct rsc *rsci; 850 }; 851 852 static int 853 svcauth_gss_set_client(struct svc_rqst *rqstp) 854 { 855 struct gss_svc_data *svcdata = rqstp->rq_auth_data; 856 struct rsc *rsci = svcdata->rsci; 857 struct rpc_gss_wire_cred *gc = &svcdata->clcred; 858 859 rqstp->rq_client = find_gss_auth_domain(rsci->mechctx, gc->gc_svc); 860 if (rqstp->rq_client == NULL) 861 return SVC_DENIED; 862 return SVC_OK; 863 } 864 865 static inline int 866 gss_write_init_verf(struct svc_rqst *rqstp, struct rsi *rsip) 867 { 868 struct rsc *rsci; 869 870 if (rsip->major_status != GSS_S_COMPLETE) 871 return gss_write_null_verf(rqstp); 872 rsci = gss_svc_searchbyctx(&rsip->out_handle); 873 if (rsci == NULL) { 874 rsip->major_status = GSS_S_NO_CONTEXT; 875 return gss_write_null_verf(rqstp); 876 } 877 return gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN); 878 } 879 880 /* 881 * Accept an rpcsec packet. 882 * If context establishment, punt to user space 883 * If data exchange, verify/decrypt 884 * If context destruction, handle here 885 * In the context establishment and destruction case we encode 886 * response here and return SVC_COMPLETE. 887 */ 888 static int 889 svcauth_gss_accept(struct svc_rqst *rqstp, u32 *authp) 890 { 891 struct kvec *argv = &rqstp->rq_arg.head[0]; 892 struct kvec *resv = &rqstp->rq_res.head[0]; 893 u32 crlen; 894 struct xdr_netobj tmpobj; 895 struct gss_svc_data *svcdata = rqstp->rq_auth_data; 896 struct rpc_gss_wire_cred *gc; 897 struct rsc *rsci = NULL; 898 struct rsi *rsip, rsikey; 899 u32 *rpcstart; 900 u32 *reject_stat = resv->iov_base + resv->iov_len; 901 int ret; 902 903 dprintk("RPC: svcauth_gss: argv->iov_len = %zd\n",argv->iov_len); 904 905 *authp = rpc_autherr_badcred; 906 if (!svcdata) 907 svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL); 908 if (!svcdata) 909 goto auth_err; 910 rqstp->rq_auth_data = svcdata; 911 svcdata->body_start = NULL; 912 svcdata->rsci = NULL; 913 gc = &svcdata->clcred; 914 915 /* start of rpc packet is 7 u32's back from here: 916 * xid direction rpcversion prog vers proc flavour 917 */ 918 rpcstart = argv->iov_base; 919 rpcstart -= 7; 920 921 /* credential is: 922 * version(==1), proc(0,1,2,3), seq, service (1,2,3), handle 923 * at least 5 u32s, and is preceeded by length, so that makes 6. 924 */ 925 926 if (argv->iov_len < 5 * 4) 927 goto auth_err; 928 crlen = ntohl(svc_getu32(argv)); 929 if (ntohl(svc_getu32(argv)) != RPC_GSS_VERSION) 930 goto auth_err; 931 gc->gc_proc = ntohl(svc_getu32(argv)); 932 gc->gc_seq = ntohl(svc_getu32(argv)); 933 gc->gc_svc = ntohl(svc_getu32(argv)); 934 if (svc_safe_getnetobj(argv, &gc->gc_ctx)) 935 goto auth_err; 936 if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4) 937 goto auth_err; 938 939 if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0)) 940 goto auth_err; 941 942 /* 943 * We've successfully parsed the credential. Let's check out the 944 * verifier. An AUTH_NULL verifier is allowed (and required) for 945 * INIT and CONTINUE_INIT requests. AUTH_RPCSEC_GSS is required for 946 * PROC_DATA and PROC_DESTROY. 947 * 948 * AUTH_NULL verifier is 0 (AUTH_NULL), 0 (length). 949 * AUTH_RPCSEC_GSS verifier is: 950 * 6 (AUTH_RPCSEC_GSS), length, checksum. 951 * checksum is calculated over rpcheader from xid up to here. 952 */ 953 *authp = rpc_autherr_badverf; 954 switch (gc->gc_proc) { 955 case RPC_GSS_PROC_INIT: 956 case RPC_GSS_PROC_CONTINUE_INIT: 957 if (argv->iov_len < 2 * 4) 958 goto auth_err; 959 if (ntohl(svc_getu32(argv)) != RPC_AUTH_NULL) 960 goto auth_err; 961 if (ntohl(svc_getu32(argv)) != 0) 962 goto auth_err; 963 break; 964 case RPC_GSS_PROC_DATA: 965 case RPC_GSS_PROC_DESTROY: 966 *authp = rpcsec_gsserr_credproblem; 967 rsci = gss_svc_searchbyctx(&gc->gc_ctx); 968 if (!rsci) 969 goto auth_err; 970 switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) { 971 case SVC_OK: 972 break; 973 case SVC_DENIED: 974 goto auth_err; 975 case SVC_DROP: 976 goto drop; 977 } 978 break; 979 default: 980 *authp = rpc_autherr_rejectedcred; 981 goto auth_err; 982 } 983 984 /* now act upon the command: */ 985 switch (gc->gc_proc) { 986 case RPC_GSS_PROC_INIT: 987 case RPC_GSS_PROC_CONTINUE_INIT: 988 *authp = rpc_autherr_badcred; 989 if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0) 990 goto auth_err; 991 memset(&rsikey, 0, sizeof(rsikey)); 992 if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx)) 993 goto drop; 994 *authp = rpc_autherr_badverf; 995 if (svc_safe_getnetobj(argv, &tmpobj)) { 996 kfree(rsikey.in_handle.data); 997 goto auth_err; 998 } 999 if (dup_netobj(&rsikey.in_token, &tmpobj)) { 1000 kfree(rsikey.in_handle.data); 1001 goto drop; 1002 } 1003 1004 rsip = rsi_lookup(&rsikey); 1005 rsi_free(&rsikey); 1006 if (!rsip) { 1007 goto drop; 1008 } 1009 switch(cache_check(&rsi_cache, &rsip->h, &rqstp->rq_chandle)) { 1010 case -EAGAIN: 1011 goto drop; 1012 case -ENOENT: 1013 goto drop; 1014 case 0: 1015 if (gss_write_init_verf(rqstp, rsip)) 1016 goto drop; 1017 if (resv->iov_len + 4 > PAGE_SIZE) 1018 goto drop; 1019 svc_putu32(resv, rpc_success); 1020 if (svc_safe_putnetobj(resv, &rsip->out_handle)) 1021 goto drop; 1022 if (resv->iov_len + 3 * 4 > PAGE_SIZE) 1023 goto drop; 1024 svc_putu32(resv, htonl(rsip->major_status)); 1025 svc_putu32(resv, htonl(rsip->minor_status)); 1026 svc_putu32(resv, htonl(GSS_SEQ_WIN)); 1027 if (svc_safe_putnetobj(resv, &rsip->out_token)) 1028 goto drop; 1029 rqstp->rq_client = NULL; 1030 } 1031 goto complete; 1032 case RPC_GSS_PROC_DESTROY: 1033 set_bit(CACHE_NEGATIVE, &rsci->h.flags); 1034 if (resv->iov_len + 4 > PAGE_SIZE) 1035 goto drop; 1036 svc_putu32(resv, rpc_success); 1037 goto complete; 1038 case RPC_GSS_PROC_DATA: 1039 *authp = rpcsec_gsserr_ctxproblem; 1040 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq)) 1041 goto auth_err; 1042 rqstp->rq_cred = rsci->cred; 1043 get_group_info(rsci->cred.cr_group_info); 1044 *authp = rpc_autherr_badcred; 1045 switch (gc->gc_svc) { 1046 case RPC_GSS_SVC_NONE: 1047 break; 1048 case RPC_GSS_SVC_INTEGRITY: 1049 if (unwrap_integ_data(&rqstp->rq_arg, 1050 gc->gc_seq, rsci->mechctx)) 1051 goto auth_err; 1052 /* placeholders for length and seq. number: */ 1053 svcdata->body_start = resv->iov_base + resv->iov_len; 1054 svc_putu32(resv, 0); 1055 svc_putu32(resv, 0); 1056 break; 1057 case RPC_GSS_SVC_PRIVACY: 1058 /* currently unsupported */ 1059 default: 1060 goto auth_err; 1061 } 1062 svcdata->rsci = rsci; 1063 cache_get(&rsci->h); 1064 ret = SVC_OK; 1065 goto out; 1066 } 1067 auth_err: 1068 /* Restore write pointer to original value: */ 1069 xdr_ressize_check(rqstp, reject_stat); 1070 ret = SVC_DENIED; 1071 goto out; 1072 complete: 1073 ret = SVC_COMPLETE; 1074 goto out; 1075 drop: 1076 ret = SVC_DROP; 1077 out: 1078 if (rsci) 1079 rsc_put(&rsci->h, &rsc_cache); 1080 return ret; 1081 } 1082 1083 static int 1084 svcauth_gss_release(struct svc_rqst *rqstp) 1085 { 1086 struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data; 1087 struct rpc_gss_wire_cred *gc = &gsd->clcred; 1088 struct xdr_buf *resbuf = &rqstp->rq_res; 1089 struct xdr_buf integ_buf; 1090 struct xdr_netobj mic; 1091 struct kvec *resv; 1092 u32 *p; 1093 int integ_offset, integ_len; 1094 int stat = -EINVAL; 1095 1096 if (gc->gc_proc != RPC_GSS_PROC_DATA) 1097 goto out; 1098 /* Release can be called twice, but we only wrap once. */ 1099 if (gsd->body_start == NULL) 1100 goto out; 1101 /* normally not set till svc_send, but we need it here: */ 1102 resbuf->len = resbuf->head[0].iov_len 1103 + resbuf->page_len + resbuf->tail[0].iov_len; 1104 switch (gc->gc_svc) { 1105 case RPC_GSS_SVC_NONE: 1106 break; 1107 case RPC_GSS_SVC_INTEGRITY: 1108 p = gsd->body_start; 1109 gsd->body_start = NULL; 1110 /* move accept_stat to right place: */ 1111 memcpy(p, p + 2, 4); 1112 /* don't wrap in failure case: */ 1113 /* Note: counting on not getting here if call was not even 1114 * accepted! */ 1115 if (*p != rpc_success) { 1116 resbuf->head[0].iov_len -= 2 * 4; 1117 goto out; 1118 } 1119 p++; 1120 integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base; 1121 integ_len = resbuf->len - integ_offset; 1122 BUG_ON(integ_len % 4); 1123 *p++ = htonl(integ_len); 1124 *p++ = htonl(gc->gc_seq); 1125 if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, 1126 integ_len)) 1127 BUG(); 1128 if (resbuf->page_len == 0 1129 && resbuf->tail[0].iov_len + RPC_MAX_AUTH_SIZE 1130 < PAGE_SIZE) { 1131 BUG_ON(resbuf->tail[0].iov_len); 1132 /* Use head for everything */ 1133 resv = &resbuf->head[0]; 1134 } else if (resbuf->tail[0].iov_base == NULL) { 1135 /* copied from nfsd4_encode_read */ 1136 svc_take_page(rqstp); 1137 resbuf->tail[0].iov_base = page_address(rqstp 1138 ->rq_respages[rqstp->rq_resused-1]); 1139 rqstp->rq_restailpage = rqstp->rq_resused-1; 1140 resbuf->tail[0].iov_len = 0; 1141 resv = &resbuf->tail[0]; 1142 } else { 1143 resv = &resbuf->tail[0]; 1144 } 1145 mic.data = (u8 *)resv->iov_base + resv->iov_len + 4; 1146 if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic)) 1147 goto out_err; 1148 svc_putu32(resv, htonl(mic.len)); 1149 memset(mic.data + mic.len, 0, 1150 round_up_to_quad(mic.len) - mic.len); 1151 resv->iov_len += XDR_QUADLEN(mic.len) << 2; 1152 /* not strictly required: */ 1153 resbuf->len += XDR_QUADLEN(mic.len) << 2; 1154 BUG_ON(resv->iov_len > PAGE_SIZE); 1155 break; 1156 case RPC_GSS_SVC_PRIVACY: 1157 default: 1158 goto out_err; 1159 } 1160 1161 out: 1162 stat = 0; 1163 out_err: 1164 if (rqstp->rq_client) 1165 auth_domain_put(rqstp->rq_client); 1166 rqstp->rq_client = NULL; 1167 if (rqstp->rq_cred.cr_group_info) 1168 put_group_info(rqstp->rq_cred.cr_group_info); 1169 rqstp->rq_cred.cr_group_info = NULL; 1170 if (gsd->rsci) 1171 rsc_put(&gsd->rsci->h, &rsc_cache); 1172 gsd->rsci = NULL; 1173 1174 return stat; 1175 } 1176 1177 static void 1178 svcauth_gss_domain_release(struct auth_domain *dom) 1179 { 1180 struct gss_domain *gd = container_of(dom, struct gss_domain, h); 1181 1182 kfree(dom->name); 1183 kfree(gd); 1184 } 1185 1186 static struct auth_ops svcauthops_gss = { 1187 .name = "rpcsec_gss", 1188 .owner = THIS_MODULE, 1189 .flavour = RPC_AUTH_GSS, 1190 .accept = svcauth_gss_accept, 1191 .release = svcauth_gss_release, 1192 .domain_release = svcauth_gss_domain_release, 1193 .set_client = svcauth_gss_set_client, 1194 }; 1195 1196 int 1197 gss_svc_init(void) 1198 { 1199 int rv = svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss); 1200 if (rv == 0) { 1201 cache_register(&rsc_cache); 1202 cache_register(&rsi_cache); 1203 } 1204 return rv; 1205 } 1206 1207 void 1208 gss_svc_shutdown(void) 1209 { 1210 if (cache_unregister(&rsc_cache)) 1211 printk(KERN_ERR "auth_rpcgss: failed to unregister rsc cache\n"); 1212 if (cache_unregister(&rsi_cache)) 1213 printk(KERN_ERR "auth_rpcgss: failed to unregister rsi cache\n"); 1214 svc_auth_unregister(RPC_AUTH_GSS); 1215 } 1216