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