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