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/slab.h> 41 #include <linux/types.h> 42 #include <linux/module.h> 43 #include <linux/pagemap.h> 44 #include <linux/user_namespace.h> 45 46 #include <linux/sunrpc/auth_gss.h> 47 #include <linux/sunrpc/gss_err.h> 48 #include <linux/sunrpc/svcauth.h> 49 #include <linux/sunrpc/svcauth_gss.h> 50 #include <linux/sunrpc/cache.h> 51 #include "gss_rpc_upcall.h" 52 53 54 #ifdef RPC_DEBUG 55 # define RPCDBG_FACILITY RPCDBG_AUTH 56 #endif 57 58 /* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests 59 * into replies. 60 * 61 * Key is context handle (\x if empty) and gss_token. 62 * Content is major_status minor_status (integers) context_handle, reply_token. 63 * 64 */ 65 66 static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b) 67 { 68 return a->len == b->len && 0 == memcmp(a->data, b->data, a->len); 69 } 70 71 #define RSI_HASHBITS 6 72 #define RSI_HASHMAX (1<<RSI_HASHBITS) 73 74 struct rsi { 75 struct cache_head h; 76 struct xdr_netobj in_handle, in_token; 77 struct xdr_netobj out_handle, out_token; 78 int major_status, minor_status; 79 }; 80 81 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old); 82 static struct rsi *rsi_lookup(struct cache_detail *cd, 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 ? kmemdup(src, len, GFP_KERNEL) : NULL); 117 if (len && !dst->data) 118 return -ENOMEM; 119 return 0; 120 } 121 122 static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src) 123 { 124 return dup_to_netobj(dst, src->data, src->len); 125 } 126 127 static void rsi_init(struct cache_head *cnew, struct cache_head *citem) 128 { 129 struct rsi *new = container_of(cnew, struct rsi, h); 130 struct rsi *item = container_of(citem, struct rsi, h); 131 132 new->out_handle.data = NULL; 133 new->out_handle.len = 0; 134 new->out_token.data = NULL; 135 new->out_token.len = 0; 136 new->in_handle.len = item->in_handle.len; 137 item->in_handle.len = 0; 138 new->in_token.len = item->in_token.len; 139 item->in_token.len = 0; 140 new->in_handle.data = item->in_handle.data; 141 item->in_handle.data = NULL; 142 new->in_token.data = item->in_token.data; 143 item->in_token.data = NULL; 144 } 145 146 static void update_rsi(struct cache_head *cnew, struct cache_head *citem) 147 { 148 struct rsi *new = container_of(cnew, struct rsi, h); 149 struct rsi *item = container_of(citem, struct rsi, h); 150 151 BUG_ON(new->out_handle.data || new->out_token.data); 152 new->out_handle.len = item->out_handle.len; 153 item->out_handle.len = 0; 154 new->out_token.len = item->out_token.len; 155 item->out_token.len = 0; 156 new->out_handle.data = item->out_handle.data; 157 item->out_handle.data = NULL; 158 new->out_token.data = item->out_token.data; 159 item->out_token.data = NULL; 160 161 new->major_status = item->major_status; 162 new->minor_status = item->minor_status; 163 } 164 165 static struct cache_head *rsi_alloc(void) 166 { 167 struct rsi *rsii = kmalloc(sizeof(*rsii), GFP_KERNEL); 168 if (rsii) 169 return &rsii->h; 170 else 171 return NULL; 172 } 173 174 static void rsi_request(struct cache_detail *cd, 175 struct cache_head *h, 176 char **bpp, int *blen) 177 { 178 struct rsi *rsii = container_of(h, struct rsi, h); 179 180 qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len); 181 qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len); 182 (*bpp)[-1] = '\n'; 183 } 184 185 static int rsi_parse(struct cache_detail *cd, 186 char *mesg, int mlen) 187 { 188 /* context token expiry major minor context token */ 189 char *buf = mesg; 190 char *ep; 191 int len; 192 struct rsi rsii, *rsip = NULL; 193 time_t expiry; 194 int status = -EINVAL; 195 196 memset(&rsii, 0, sizeof(rsii)); 197 /* handle */ 198 len = qword_get(&mesg, buf, mlen); 199 if (len < 0) 200 goto out; 201 status = -ENOMEM; 202 if (dup_to_netobj(&rsii.in_handle, buf, len)) 203 goto out; 204 205 /* token */ 206 len = qword_get(&mesg, buf, mlen); 207 status = -EINVAL; 208 if (len < 0) 209 goto out; 210 status = -ENOMEM; 211 if (dup_to_netobj(&rsii.in_token, buf, len)) 212 goto out; 213 214 rsip = rsi_lookup(cd, &rsii); 215 if (!rsip) 216 goto out; 217 218 rsii.h.flags = 0; 219 /* expiry */ 220 expiry = get_expiry(&mesg); 221 status = -EINVAL; 222 if (expiry == 0) 223 goto out; 224 225 /* major/minor */ 226 len = qword_get(&mesg, buf, mlen); 227 if (len <= 0) 228 goto out; 229 rsii.major_status = simple_strtoul(buf, &ep, 10); 230 if (*ep) 231 goto out; 232 len = qword_get(&mesg, buf, mlen); 233 if (len <= 0) 234 goto out; 235 rsii.minor_status = simple_strtoul(buf, &ep, 10); 236 if (*ep) 237 goto out; 238 239 /* out_handle */ 240 len = qword_get(&mesg, buf, mlen); 241 if (len < 0) 242 goto out; 243 status = -ENOMEM; 244 if (dup_to_netobj(&rsii.out_handle, buf, len)) 245 goto out; 246 247 /* out_token */ 248 len = qword_get(&mesg, buf, mlen); 249 status = -EINVAL; 250 if (len < 0) 251 goto out; 252 status = -ENOMEM; 253 if (dup_to_netobj(&rsii.out_token, buf, len)) 254 goto out; 255 rsii.h.expiry_time = expiry; 256 rsip = rsi_update(cd, &rsii, rsip); 257 status = 0; 258 out: 259 rsi_free(&rsii); 260 if (rsip) 261 cache_put(&rsip->h, cd); 262 else 263 status = -ENOMEM; 264 return status; 265 } 266 267 static struct cache_detail rsi_cache_template = { 268 .owner = THIS_MODULE, 269 .hash_size = RSI_HASHMAX, 270 .name = "auth.rpcsec.init", 271 .cache_put = rsi_put, 272 .cache_request = rsi_request, 273 .cache_parse = rsi_parse, 274 .match = rsi_match, 275 .init = rsi_init, 276 .update = update_rsi, 277 .alloc = rsi_alloc, 278 }; 279 280 static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item) 281 { 282 struct cache_head *ch; 283 int hash = rsi_hash(item); 284 285 ch = sunrpc_cache_lookup(cd, &item->h, hash); 286 if (ch) 287 return container_of(ch, struct rsi, h); 288 else 289 return NULL; 290 } 291 292 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old) 293 { 294 struct cache_head *ch; 295 int hash = rsi_hash(new); 296 297 ch = sunrpc_cache_update(cd, &new->h, 298 &old->h, hash); 299 if (ch) 300 return container_of(ch, struct rsi, h); 301 else 302 return NULL; 303 } 304 305 306 /* 307 * The rpcsec_context cache is used to store a context that is 308 * used in data exchange. 309 * The key is a context handle. The content is: 310 * uid, gidlist, mechanism, service-set, mech-specific-data 311 */ 312 313 #define RSC_HASHBITS 10 314 #define RSC_HASHMAX (1<<RSC_HASHBITS) 315 316 #define GSS_SEQ_WIN 128 317 318 struct gss_svc_seq_data { 319 /* highest seq number seen so far: */ 320 int sd_max; 321 /* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of 322 * sd_win is nonzero iff sequence number i has been seen already: */ 323 unsigned long sd_win[GSS_SEQ_WIN/BITS_PER_LONG]; 324 spinlock_t sd_lock; 325 }; 326 327 struct rsc { 328 struct cache_head h; 329 struct xdr_netobj handle; 330 struct svc_cred cred; 331 struct gss_svc_seq_data seqdata; 332 struct gss_ctx *mechctx; 333 }; 334 335 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old); 336 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item); 337 338 static void rsc_free(struct rsc *rsci) 339 { 340 kfree(rsci->handle.data); 341 if (rsci->mechctx) 342 gss_delete_sec_context(&rsci->mechctx); 343 free_svc_cred(&rsci->cred); 344 } 345 346 static void rsc_put(struct kref *ref) 347 { 348 struct rsc *rsci = container_of(ref, struct rsc, h.ref); 349 350 rsc_free(rsci); 351 kfree(rsci); 352 } 353 354 static inline int 355 rsc_hash(struct rsc *rsci) 356 { 357 return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS); 358 } 359 360 static int 361 rsc_match(struct cache_head *a, struct cache_head *b) 362 { 363 struct rsc *new = container_of(a, struct rsc, h); 364 struct rsc *tmp = container_of(b, struct rsc, h); 365 366 return netobj_equal(&new->handle, &tmp->handle); 367 } 368 369 static void 370 rsc_init(struct cache_head *cnew, struct cache_head *ctmp) 371 { 372 struct rsc *new = container_of(cnew, struct rsc, h); 373 struct rsc *tmp = container_of(ctmp, struct rsc, h); 374 375 new->handle.len = tmp->handle.len; 376 tmp->handle.len = 0; 377 new->handle.data = tmp->handle.data; 378 tmp->handle.data = NULL; 379 new->mechctx = NULL; 380 init_svc_cred(&new->cred); 381 } 382 383 static void 384 update_rsc(struct cache_head *cnew, struct cache_head *ctmp) 385 { 386 struct rsc *new = container_of(cnew, struct rsc, h); 387 struct rsc *tmp = container_of(ctmp, struct rsc, h); 388 389 new->mechctx = tmp->mechctx; 390 tmp->mechctx = NULL; 391 memset(&new->seqdata, 0, sizeof(new->seqdata)); 392 spin_lock_init(&new->seqdata.sd_lock); 393 new->cred = tmp->cred; 394 new->cred.cr_principal = tmp->cred.cr_principal; 395 init_svc_cred(&tmp->cred); 396 } 397 398 static struct cache_head * 399 rsc_alloc(void) 400 { 401 struct rsc *rsci = kmalloc(sizeof(*rsci), GFP_KERNEL); 402 if (rsci) 403 return &rsci->h; 404 else 405 return NULL; 406 } 407 408 static int rsc_parse(struct cache_detail *cd, 409 char *mesg, int mlen) 410 { 411 /* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */ 412 char *buf = mesg; 413 int id; 414 int len, rv; 415 struct rsc rsci, *rscp = NULL; 416 time_t expiry; 417 int status = -EINVAL; 418 struct gss_api_mech *gm = NULL; 419 420 memset(&rsci, 0, sizeof(rsci)); 421 /* context handle */ 422 len = qword_get(&mesg, buf, mlen); 423 if (len < 0) goto out; 424 status = -ENOMEM; 425 if (dup_to_netobj(&rsci.handle, buf, len)) 426 goto out; 427 428 rsci.h.flags = 0; 429 /* expiry */ 430 expiry = get_expiry(&mesg); 431 status = -EINVAL; 432 if (expiry == 0) 433 goto out; 434 435 rscp = rsc_lookup(cd, &rsci); 436 if (!rscp) 437 goto out; 438 439 /* uid, or NEGATIVE */ 440 rv = get_int(&mesg, &id); 441 if (rv == -EINVAL) 442 goto out; 443 if (rv == -ENOENT) 444 set_bit(CACHE_NEGATIVE, &rsci.h.flags); 445 else { 446 int N, i; 447 448 /* 449 * NOTE: we skip uid_valid()/gid_valid() checks here: 450 * instead, * -1 id's are later mapped to the 451 * (export-specific) anonymous id by nfsd_setuser. 452 * 453 * (But supplementary gid's get no such special 454 * treatment so are checked for validity here.) 455 */ 456 /* uid */ 457 rsci.cred.cr_uid = make_kuid(&init_user_ns, id); 458 459 /* gid */ 460 if (get_int(&mesg, &id)) 461 goto out; 462 rsci.cred.cr_gid = make_kgid(&init_user_ns, id); 463 464 /* number of additional gid's */ 465 if (get_int(&mesg, &N)) 466 goto out; 467 status = -ENOMEM; 468 rsci.cred.cr_group_info = groups_alloc(N); 469 if (rsci.cred.cr_group_info == NULL) 470 goto out; 471 472 /* gid's */ 473 status = -EINVAL; 474 for (i=0; i<N; i++) { 475 kgid_t kgid; 476 if (get_int(&mesg, &id)) 477 goto out; 478 kgid = make_kgid(&init_user_ns, id); 479 if (!gid_valid(kgid)) 480 goto out; 481 GROUP_AT(rsci.cred.cr_group_info, i) = kgid; 482 } 483 484 /* mech name */ 485 len = qword_get(&mesg, buf, mlen); 486 if (len < 0) 487 goto out; 488 gm = gss_mech_get_by_name(buf); 489 status = -EOPNOTSUPP; 490 if (!gm) 491 goto out; 492 493 status = -EINVAL; 494 /* mech-specific data: */ 495 len = qword_get(&mesg, buf, mlen); 496 if (len < 0) 497 goto out; 498 status = gss_import_sec_context(buf, len, gm, &rsci.mechctx, 499 NULL, GFP_KERNEL); 500 if (status) 501 goto out; 502 503 /* get client name */ 504 len = qword_get(&mesg, buf, mlen); 505 if (len > 0) { 506 rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL); 507 if (!rsci.cred.cr_principal) { 508 status = -ENOMEM; 509 goto out; 510 } 511 } 512 513 } 514 rsci.h.expiry_time = expiry; 515 rscp = rsc_update(cd, &rsci, rscp); 516 status = 0; 517 out: 518 gss_mech_put(gm); 519 rsc_free(&rsci); 520 if (rscp) 521 cache_put(&rscp->h, cd); 522 else 523 status = -ENOMEM; 524 return status; 525 } 526 527 static struct cache_detail rsc_cache_template = { 528 .owner = THIS_MODULE, 529 .hash_size = RSC_HASHMAX, 530 .name = "auth.rpcsec.context", 531 .cache_put = rsc_put, 532 .cache_parse = rsc_parse, 533 .match = rsc_match, 534 .init = rsc_init, 535 .update = update_rsc, 536 .alloc = rsc_alloc, 537 }; 538 539 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item) 540 { 541 struct cache_head *ch; 542 int hash = rsc_hash(item); 543 544 ch = sunrpc_cache_lookup(cd, &item->h, hash); 545 if (ch) 546 return container_of(ch, struct rsc, h); 547 else 548 return NULL; 549 } 550 551 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old) 552 { 553 struct cache_head *ch; 554 int hash = rsc_hash(new); 555 556 ch = sunrpc_cache_update(cd, &new->h, 557 &old->h, hash); 558 if (ch) 559 return container_of(ch, struct rsc, h); 560 else 561 return NULL; 562 } 563 564 565 static struct rsc * 566 gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle) 567 { 568 struct rsc rsci; 569 struct rsc *found; 570 571 memset(&rsci, 0, sizeof(rsci)); 572 if (dup_to_netobj(&rsci.handle, handle->data, handle->len)) 573 return NULL; 574 found = rsc_lookup(cd, &rsci); 575 rsc_free(&rsci); 576 if (!found) 577 return NULL; 578 if (cache_check(cd, &found->h, NULL)) 579 return NULL; 580 return found; 581 } 582 583 /* Implements sequence number algorithm as specified in RFC 2203. */ 584 static int 585 gss_check_seq_num(struct rsc *rsci, int seq_num) 586 { 587 struct gss_svc_seq_data *sd = &rsci->seqdata; 588 589 spin_lock(&sd->sd_lock); 590 if (seq_num > sd->sd_max) { 591 if (seq_num >= sd->sd_max + GSS_SEQ_WIN) { 592 memset(sd->sd_win,0,sizeof(sd->sd_win)); 593 sd->sd_max = seq_num; 594 } else while (sd->sd_max < seq_num) { 595 sd->sd_max++; 596 __clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win); 597 } 598 __set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win); 599 goto ok; 600 } else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) { 601 goto drop; 602 } 603 /* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */ 604 if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win)) 605 goto drop; 606 ok: 607 spin_unlock(&sd->sd_lock); 608 return 1; 609 drop: 610 spin_unlock(&sd->sd_lock); 611 return 0; 612 } 613 614 static inline u32 round_up_to_quad(u32 i) 615 { 616 return (i + 3 ) & ~3; 617 } 618 619 static inline int 620 svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o) 621 { 622 int l; 623 624 if (argv->iov_len < 4) 625 return -1; 626 o->len = svc_getnl(argv); 627 l = round_up_to_quad(o->len); 628 if (argv->iov_len < l) 629 return -1; 630 o->data = argv->iov_base; 631 argv->iov_base += l; 632 argv->iov_len -= l; 633 return 0; 634 } 635 636 static inline int 637 svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o) 638 { 639 u8 *p; 640 641 if (resv->iov_len + 4 > PAGE_SIZE) 642 return -1; 643 svc_putnl(resv, o->len); 644 p = resv->iov_base + resv->iov_len; 645 resv->iov_len += round_up_to_quad(o->len); 646 if (resv->iov_len > PAGE_SIZE) 647 return -1; 648 memcpy(p, o->data, o->len); 649 memset(p + o->len, 0, round_up_to_quad(o->len) - o->len); 650 return 0; 651 } 652 653 /* 654 * Verify the checksum on the header and return SVC_OK on success. 655 * Otherwise, return SVC_DROP (in the case of a bad sequence number) 656 * or return SVC_DENIED and indicate error in authp. 657 */ 658 static int 659 gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci, 660 __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp) 661 { 662 struct gss_ctx *ctx_id = rsci->mechctx; 663 struct xdr_buf rpchdr; 664 struct xdr_netobj checksum; 665 u32 flavor = 0; 666 struct kvec *argv = &rqstp->rq_arg.head[0]; 667 struct kvec iov; 668 669 /* data to compute the checksum over: */ 670 iov.iov_base = rpcstart; 671 iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart; 672 xdr_buf_from_iov(&iov, &rpchdr); 673 674 *authp = rpc_autherr_badverf; 675 if (argv->iov_len < 4) 676 return SVC_DENIED; 677 flavor = svc_getnl(argv); 678 if (flavor != RPC_AUTH_GSS) 679 return SVC_DENIED; 680 if (svc_safe_getnetobj(argv, &checksum)) 681 return SVC_DENIED; 682 683 if (rqstp->rq_deferred) /* skip verification of revisited request */ 684 return SVC_OK; 685 if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) { 686 *authp = rpcsec_gsserr_credproblem; 687 return SVC_DENIED; 688 } 689 690 if (gc->gc_seq > MAXSEQ) { 691 dprintk("RPC: svcauth_gss: discarding request with " 692 "large sequence number %d\n", gc->gc_seq); 693 *authp = rpcsec_gsserr_ctxproblem; 694 return SVC_DENIED; 695 } 696 if (!gss_check_seq_num(rsci, gc->gc_seq)) { 697 dprintk("RPC: svcauth_gss: discarding request with " 698 "old sequence number %d\n", gc->gc_seq); 699 return SVC_DROP; 700 } 701 return SVC_OK; 702 } 703 704 static int 705 gss_write_null_verf(struct svc_rqst *rqstp) 706 { 707 __be32 *p; 708 709 svc_putnl(rqstp->rq_res.head, RPC_AUTH_NULL); 710 p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len; 711 /* don't really need to check if head->iov_len > PAGE_SIZE ... */ 712 *p++ = 0; 713 if (!xdr_ressize_check(rqstp, p)) 714 return -1; 715 return 0; 716 } 717 718 static int 719 gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq) 720 { 721 __be32 xdr_seq; 722 u32 maj_stat; 723 struct xdr_buf verf_data; 724 struct xdr_netobj mic; 725 __be32 *p; 726 struct kvec iov; 727 728 svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS); 729 xdr_seq = htonl(seq); 730 731 iov.iov_base = &xdr_seq; 732 iov.iov_len = sizeof(xdr_seq); 733 xdr_buf_from_iov(&iov, &verf_data); 734 p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len; 735 mic.data = (u8 *)(p + 1); 736 maj_stat = gss_get_mic(ctx_id, &verf_data, &mic); 737 if (maj_stat != GSS_S_COMPLETE) 738 return -1; 739 *p++ = htonl(mic.len); 740 memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len); 741 p += XDR_QUADLEN(mic.len); 742 if (!xdr_ressize_check(rqstp, p)) 743 return -1; 744 return 0; 745 } 746 747 struct gss_domain { 748 struct auth_domain h; 749 u32 pseudoflavor; 750 }; 751 752 static struct auth_domain * 753 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc) 754 { 755 char *name; 756 757 name = gss_service_to_auth_domain_name(ctx->mech_type, svc); 758 if (!name) 759 return NULL; 760 return auth_domain_find(name); 761 } 762 763 static struct auth_ops svcauthops_gss; 764 765 u32 svcauth_gss_flavor(struct auth_domain *dom) 766 { 767 struct gss_domain *gd = container_of(dom, struct gss_domain, h); 768 769 return gd->pseudoflavor; 770 } 771 772 EXPORT_SYMBOL_GPL(svcauth_gss_flavor); 773 774 int 775 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name) 776 { 777 struct gss_domain *new; 778 struct auth_domain *test; 779 int stat = -ENOMEM; 780 781 new = kmalloc(sizeof(*new), GFP_KERNEL); 782 if (!new) 783 goto out; 784 kref_init(&new->h.ref); 785 new->h.name = kstrdup(name, GFP_KERNEL); 786 if (!new->h.name) 787 goto out_free_dom; 788 new->h.flavour = &svcauthops_gss; 789 new->pseudoflavor = pseudoflavor; 790 791 stat = 0; 792 test = auth_domain_lookup(name, &new->h); 793 if (test != &new->h) { /* Duplicate registration */ 794 auth_domain_put(test); 795 kfree(new->h.name); 796 goto out_free_dom; 797 } 798 return 0; 799 800 out_free_dom: 801 kfree(new); 802 out: 803 return stat; 804 } 805 806 EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor); 807 808 static inline int 809 read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj) 810 { 811 __be32 raw; 812 int status; 813 814 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); 815 if (status) 816 return status; 817 *obj = ntohl(raw); 818 return 0; 819 } 820 821 /* It would be nice if this bit of code could be shared with the client. 822 * Obstacles: 823 * The client shouldn't malloc(), would have to pass in own memory. 824 * The server uses base of head iovec as read pointer, while the 825 * client uses separate pointer. */ 826 static int 827 unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx) 828 { 829 int stat = -EINVAL; 830 u32 integ_len, maj_stat; 831 struct xdr_netobj mic; 832 struct xdr_buf integ_buf; 833 834 /* Did we already verify the signature on the original pass through? */ 835 if (rqstp->rq_deferred) 836 return 0; 837 838 integ_len = svc_getnl(&buf->head[0]); 839 if (integ_len & 3) 840 return stat; 841 if (integ_len > buf->len) 842 return stat; 843 if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len)) 844 BUG(); 845 /* copy out mic... */ 846 if (read_u32_from_xdr_buf(buf, integ_len, &mic.len)) 847 BUG(); 848 if (mic.len > RPC_MAX_AUTH_SIZE) 849 return stat; 850 mic.data = kmalloc(mic.len, GFP_KERNEL); 851 if (!mic.data) 852 return stat; 853 if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len)) 854 goto out; 855 maj_stat = gss_verify_mic(ctx, &integ_buf, &mic); 856 if (maj_stat != GSS_S_COMPLETE) 857 goto out; 858 if (svc_getnl(&buf->head[0]) != seq) 859 goto out; 860 /* trim off the mic at the end before returning */ 861 xdr_buf_trim(buf, mic.len + 4); 862 stat = 0; 863 out: 864 kfree(mic.data); 865 return stat; 866 } 867 868 static inline int 869 total_buf_len(struct xdr_buf *buf) 870 { 871 return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len; 872 } 873 874 static void 875 fix_priv_head(struct xdr_buf *buf, int pad) 876 { 877 if (buf->page_len == 0) { 878 /* We need to adjust head and buf->len in tandem in this 879 * case to make svc_defer() work--it finds the original 880 * buffer start using buf->len - buf->head[0].iov_len. */ 881 buf->head[0].iov_len -= pad; 882 } 883 } 884 885 static int 886 unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx) 887 { 888 u32 priv_len, maj_stat; 889 int pad, saved_len, remaining_len, offset; 890 891 rqstp->rq_splice_ok = 0; 892 893 priv_len = svc_getnl(&buf->head[0]); 894 if (rqstp->rq_deferred) { 895 /* Already decrypted last time through! The sequence number 896 * check at out_seq is unnecessary but harmless: */ 897 goto out_seq; 898 } 899 /* buf->len is the number of bytes from the original start of the 900 * request to the end, where head[0].iov_len is just the bytes 901 * not yet read from the head, so these two values are different: */ 902 remaining_len = total_buf_len(buf); 903 if (priv_len > remaining_len) 904 return -EINVAL; 905 pad = remaining_len - priv_len; 906 buf->len -= pad; 907 fix_priv_head(buf, pad); 908 909 /* Maybe it would be better to give gss_unwrap a length parameter: */ 910 saved_len = buf->len; 911 buf->len = priv_len; 912 maj_stat = gss_unwrap(ctx, 0, buf); 913 pad = priv_len - buf->len; 914 buf->len = saved_len; 915 buf->len -= pad; 916 /* The upper layers assume the buffer is aligned on 4-byte boundaries. 917 * In the krb5p case, at least, the data ends up offset, so we need to 918 * move it around. */ 919 /* XXX: This is very inefficient. It would be better to either do 920 * this while we encrypt, or maybe in the receive code, if we can peak 921 * ahead and work out the service and mechanism there. */ 922 offset = buf->head[0].iov_len % 4; 923 if (offset) { 924 buf->buflen = RPCSVC_MAXPAYLOAD; 925 xdr_shift_buf(buf, offset); 926 fix_priv_head(buf, pad); 927 } 928 if (maj_stat != GSS_S_COMPLETE) 929 return -EINVAL; 930 out_seq: 931 if (svc_getnl(&buf->head[0]) != seq) 932 return -EINVAL; 933 return 0; 934 } 935 936 struct gss_svc_data { 937 /* decoded gss client cred: */ 938 struct rpc_gss_wire_cred clcred; 939 /* save a pointer to the beginning of the encoded verifier, 940 * for use in encryption/checksumming in svcauth_gss_release: */ 941 __be32 *verf_start; 942 struct rsc *rsci; 943 }; 944 945 static int 946 svcauth_gss_set_client(struct svc_rqst *rqstp) 947 { 948 struct gss_svc_data *svcdata = rqstp->rq_auth_data; 949 struct rsc *rsci = svcdata->rsci; 950 struct rpc_gss_wire_cred *gc = &svcdata->clcred; 951 int stat; 952 953 /* 954 * A gss export can be specified either by: 955 * export *(sec=krb5,rw) 956 * or by 957 * export gss/krb5(rw) 958 * The latter is deprecated; but for backwards compatibility reasons 959 * the nfsd code will still fall back on trying it if the former 960 * doesn't work; so we try to make both available to nfsd, below. 961 */ 962 rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc); 963 if (rqstp->rq_gssclient == NULL) 964 return SVC_DENIED; 965 stat = svcauth_unix_set_client(rqstp); 966 if (stat == SVC_DROP || stat == SVC_CLOSE) 967 return stat; 968 return SVC_OK; 969 } 970 971 static inline int 972 gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp, 973 struct xdr_netobj *out_handle, int *major_status) 974 { 975 struct rsc *rsci; 976 int rc; 977 978 if (*major_status != GSS_S_COMPLETE) 979 return gss_write_null_verf(rqstp); 980 rsci = gss_svc_searchbyctx(cd, out_handle); 981 if (rsci == NULL) { 982 *major_status = GSS_S_NO_CONTEXT; 983 return gss_write_null_verf(rqstp); 984 } 985 rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN); 986 cache_put(&rsci->h, cd); 987 return rc; 988 } 989 990 static inline int 991 gss_read_common_verf(struct rpc_gss_wire_cred *gc, 992 struct kvec *argv, __be32 *authp, 993 struct xdr_netobj *in_handle) 994 { 995 /* Read the verifier; should be NULL: */ 996 *authp = rpc_autherr_badverf; 997 if (argv->iov_len < 2 * 4) 998 return SVC_DENIED; 999 if (svc_getnl(argv) != RPC_AUTH_NULL) 1000 return SVC_DENIED; 1001 if (svc_getnl(argv) != 0) 1002 return SVC_DENIED; 1003 /* Martial context handle and token for upcall: */ 1004 *authp = rpc_autherr_badcred; 1005 if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0) 1006 return SVC_DENIED; 1007 if (dup_netobj(in_handle, &gc->gc_ctx)) 1008 return SVC_CLOSE; 1009 *authp = rpc_autherr_badverf; 1010 1011 return 0; 1012 } 1013 1014 static inline int 1015 gss_read_verf(struct rpc_gss_wire_cred *gc, 1016 struct kvec *argv, __be32 *authp, 1017 struct xdr_netobj *in_handle, 1018 struct xdr_netobj *in_token) 1019 { 1020 struct xdr_netobj tmpobj; 1021 int res; 1022 1023 res = gss_read_common_verf(gc, argv, authp, in_handle); 1024 if (res) 1025 return res; 1026 1027 if (svc_safe_getnetobj(argv, &tmpobj)) { 1028 kfree(in_handle->data); 1029 return SVC_DENIED; 1030 } 1031 if (dup_netobj(in_token, &tmpobj)) { 1032 kfree(in_handle->data); 1033 return SVC_CLOSE; 1034 } 1035 1036 return 0; 1037 } 1038 1039 /* Ok this is really heavily depending on a set of semantics in 1040 * how rqstp is set up by svc_recv and pages laid down by the 1041 * server when reading a request. We are basically guaranteed that 1042 * the token lays all down linearly across a set of pages, starting 1043 * at iov_base in rq_arg.head[0] which happens to be the first of a 1044 * set of pages stored in rq_pages[]. 1045 * rq_arg.head[0].iov_base will provide us the page_base to pass 1046 * to the upcall. 1047 */ 1048 static inline int 1049 gss_read_proxy_verf(struct svc_rqst *rqstp, 1050 struct rpc_gss_wire_cred *gc, __be32 *authp, 1051 struct xdr_netobj *in_handle, 1052 struct gssp_in_token *in_token) 1053 { 1054 struct kvec *argv = &rqstp->rq_arg.head[0]; 1055 u32 inlen; 1056 int res; 1057 1058 res = gss_read_common_verf(gc, argv, authp, in_handle); 1059 if (res) 1060 return res; 1061 1062 inlen = svc_getnl(argv); 1063 if (inlen > (argv->iov_len + rqstp->rq_arg.page_len)) 1064 return SVC_DENIED; 1065 1066 in_token->pages = rqstp->rq_pages; 1067 in_token->page_base = (ulong)argv->iov_base & ~PAGE_MASK; 1068 in_token->page_len = inlen; 1069 1070 return 0; 1071 } 1072 1073 static inline int 1074 gss_write_resv(struct kvec *resv, size_t size_limit, 1075 struct xdr_netobj *out_handle, struct xdr_netobj *out_token, 1076 int major_status, int minor_status) 1077 { 1078 if (resv->iov_len + 4 > size_limit) 1079 return -1; 1080 svc_putnl(resv, RPC_SUCCESS); 1081 if (svc_safe_putnetobj(resv, out_handle)) 1082 return -1; 1083 if (resv->iov_len + 3 * 4 > size_limit) 1084 return -1; 1085 svc_putnl(resv, major_status); 1086 svc_putnl(resv, minor_status); 1087 svc_putnl(resv, GSS_SEQ_WIN); 1088 if (svc_safe_putnetobj(resv, out_token)) 1089 return -1; 1090 return 0; 1091 } 1092 1093 /* 1094 * Having read the cred already and found we're in the context 1095 * initiation case, read the verifier and initiate (or check the results 1096 * of) upcalls to userspace for help with context initiation. If 1097 * the upcall results are available, write the verifier and result. 1098 * Otherwise, drop the request pending an answer to the upcall. 1099 */ 1100 static int svcauth_gss_legacy_init(struct svc_rqst *rqstp, 1101 struct rpc_gss_wire_cred *gc, __be32 *authp) 1102 { 1103 struct kvec *argv = &rqstp->rq_arg.head[0]; 1104 struct kvec *resv = &rqstp->rq_res.head[0]; 1105 struct rsi *rsip, rsikey; 1106 int ret; 1107 struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id); 1108 1109 memset(&rsikey, 0, sizeof(rsikey)); 1110 ret = gss_read_verf(gc, argv, authp, 1111 &rsikey.in_handle, &rsikey.in_token); 1112 if (ret) 1113 return ret; 1114 1115 /* Perform upcall, or find upcall result: */ 1116 rsip = rsi_lookup(sn->rsi_cache, &rsikey); 1117 rsi_free(&rsikey); 1118 if (!rsip) 1119 return SVC_CLOSE; 1120 if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0) 1121 /* No upcall result: */ 1122 return SVC_CLOSE; 1123 1124 ret = SVC_CLOSE; 1125 /* Got an answer to the upcall; use it: */ 1126 if (gss_write_init_verf(sn->rsc_cache, rqstp, 1127 &rsip->out_handle, &rsip->major_status)) 1128 goto out; 1129 if (gss_write_resv(resv, PAGE_SIZE, 1130 &rsip->out_handle, &rsip->out_token, 1131 rsip->major_status, rsip->minor_status)) 1132 goto out; 1133 1134 ret = SVC_COMPLETE; 1135 out: 1136 cache_put(&rsip->h, sn->rsi_cache); 1137 return ret; 1138 } 1139 1140 static int gss_proxy_save_rsc(struct cache_detail *cd, 1141 struct gssp_upcall_data *ud, 1142 uint64_t *handle) 1143 { 1144 struct rsc rsci, *rscp = NULL; 1145 static atomic64_t ctxhctr; 1146 long long ctxh; 1147 struct gss_api_mech *gm = NULL; 1148 time_t expiry; 1149 int status = -EINVAL; 1150 1151 memset(&rsci, 0, sizeof(rsci)); 1152 /* context handle */ 1153 status = -ENOMEM; 1154 /* the handle needs to be just a unique id, 1155 * use a static counter */ 1156 ctxh = atomic64_inc_return(&ctxhctr); 1157 1158 /* make a copy for the caller */ 1159 *handle = ctxh; 1160 1161 /* make a copy for the rsc cache */ 1162 if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t))) 1163 goto out; 1164 rscp = rsc_lookup(cd, &rsci); 1165 if (!rscp) 1166 goto out; 1167 1168 /* creds */ 1169 if (!ud->found_creds) { 1170 /* userspace seem buggy, we should always get at least a 1171 * mapping to nobody */ 1172 dprintk("RPC: No creds found, marking Negative!\n"); 1173 set_bit(CACHE_NEGATIVE, &rsci.h.flags); 1174 } else { 1175 1176 /* steal creds */ 1177 rsci.cred = ud->creds; 1178 memset(&ud->creds, 0, sizeof(struct svc_cred)); 1179 1180 status = -EOPNOTSUPP; 1181 /* get mech handle from OID */ 1182 gm = gss_mech_get_by_OID(&ud->mech_oid); 1183 if (!gm) 1184 goto out; 1185 1186 status = -EINVAL; 1187 /* mech-specific data: */ 1188 status = gss_import_sec_context(ud->out_handle.data, 1189 ud->out_handle.len, 1190 gm, &rsci.mechctx, 1191 &expiry, GFP_KERNEL); 1192 if (status) 1193 goto out; 1194 } 1195 1196 rsci.h.expiry_time = expiry; 1197 rscp = rsc_update(cd, &rsci, rscp); 1198 status = 0; 1199 out: 1200 gss_mech_put(gm); 1201 rsc_free(&rsci); 1202 if (rscp) 1203 cache_put(&rscp->h, cd); 1204 else 1205 status = -ENOMEM; 1206 return status; 1207 } 1208 1209 static int svcauth_gss_proxy_init(struct svc_rqst *rqstp, 1210 struct rpc_gss_wire_cred *gc, __be32 *authp) 1211 { 1212 struct kvec *resv = &rqstp->rq_res.head[0]; 1213 struct xdr_netobj cli_handle; 1214 struct gssp_upcall_data ud; 1215 uint64_t handle; 1216 int status; 1217 int ret; 1218 struct net *net = rqstp->rq_xprt->xpt_net; 1219 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1220 1221 memset(&ud, 0, sizeof(ud)); 1222 ret = gss_read_proxy_verf(rqstp, gc, authp, 1223 &ud.in_handle, &ud.in_token); 1224 if (ret) 1225 return ret; 1226 1227 ret = SVC_CLOSE; 1228 1229 /* Perform synchronous upcall to gss-proxy */ 1230 status = gssp_accept_sec_context_upcall(net, &ud); 1231 if (status) 1232 goto out; 1233 1234 dprintk("RPC: svcauth_gss: gss major status = %d\n", 1235 ud.major_status); 1236 1237 switch (ud.major_status) { 1238 case GSS_S_CONTINUE_NEEDED: 1239 cli_handle = ud.out_handle; 1240 break; 1241 case GSS_S_COMPLETE: 1242 status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle); 1243 if (status) 1244 goto out; 1245 cli_handle.data = (u8 *)&handle; 1246 cli_handle.len = sizeof(handle); 1247 break; 1248 default: 1249 ret = SVC_CLOSE; 1250 goto out; 1251 } 1252 1253 /* Got an answer to the upcall; use it: */ 1254 if (gss_write_init_verf(sn->rsc_cache, rqstp, 1255 &cli_handle, &ud.major_status)) 1256 goto out; 1257 if (gss_write_resv(resv, PAGE_SIZE, 1258 &cli_handle, &ud.out_token, 1259 ud.major_status, ud.minor_status)) 1260 goto out; 1261 1262 ret = SVC_COMPLETE; 1263 out: 1264 gssp_free_upcall_data(&ud); 1265 return ret; 1266 } 1267 1268 DEFINE_SPINLOCK(use_gssp_lock); 1269 1270 static bool use_gss_proxy(struct net *net) 1271 { 1272 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1273 1274 if (sn->use_gss_proxy != -1) 1275 return sn->use_gss_proxy; 1276 spin_lock(&use_gssp_lock); 1277 /* 1278 * If you wanted gss-proxy, you should have said so before 1279 * starting to accept requests: 1280 */ 1281 sn->use_gss_proxy = 0; 1282 spin_unlock(&use_gssp_lock); 1283 return 0; 1284 } 1285 1286 #ifdef CONFIG_PROC_FS 1287 1288 static int set_gss_proxy(struct net *net, int type) 1289 { 1290 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1291 int ret = 0; 1292 1293 WARN_ON_ONCE(type != 0 && type != 1); 1294 spin_lock(&use_gssp_lock); 1295 if (sn->use_gss_proxy == -1 || sn->use_gss_proxy == type) 1296 sn->use_gss_proxy = type; 1297 else 1298 ret = -EBUSY; 1299 spin_unlock(&use_gssp_lock); 1300 wake_up(&sn->gssp_wq); 1301 return ret; 1302 } 1303 1304 static inline bool gssp_ready(struct sunrpc_net *sn) 1305 { 1306 switch (sn->use_gss_proxy) { 1307 case -1: 1308 return false; 1309 case 0: 1310 return true; 1311 case 1: 1312 return sn->gssp_clnt; 1313 } 1314 WARN_ON_ONCE(1); 1315 return false; 1316 } 1317 1318 static int wait_for_gss_proxy(struct net *net, struct file *file) 1319 { 1320 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1321 1322 if (file->f_flags & O_NONBLOCK && !gssp_ready(sn)) 1323 return -EAGAIN; 1324 return wait_event_interruptible(sn->gssp_wq, gssp_ready(sn)); 1325 } 1326 1327 1328 static ssize_t write_gssp(struct file *file, const char __user *buf, 1329 size_t count, loff_t *ppos) 1330 { 1331 struct net *net = PDE_DATA(file->f_path.dentry->d_inode); 1332 char tbuf[20]; 1333 unsigned long i; 1334 int res; 1335 1336 if (*ppos || count > sizeof(tbuf)-1) 1337 return -EINVAL; 1338 if (copy_from_user(tbuf, buf, count)) 1339 return -EFAULT; 1340 1341 tbuf[count] = 0; 1342 res = kstrtoul(tbuf, 0, &i); 1343 if (res) 1344 return res; 1345 if (i != 1) 1346 return -EINVAL; 1347 res = set_gss_proxy(net, 1); 1348 if (res) 1349 return res; 1350 res = set_gssp_clnt(net); 1351 if (res) 1352 return res; 1353 return count; 1354 } 1355 1356 static ssize_t read_gssp(struct file *file, char __user *buf, 1357 size_t count, loff_t *ppos) 1358 { 1359 struct net *net = PDE_DATA(file->f_path.dentry->d_inode); 1360 unsigned long p = *ppos; 1361 char tbuf[10]; 1362 size_t len; 1363 int ret; 1364 1365 ret = wait_for_gss_proxy(net, file); 1366 if (ret) 1367 return ret; 1368 1369 snprintf(tbuf, sizeof(tbuf), "%d\n", use_gss_proxy(net)); 1370 len = strlen(tbuf); 1371 if (p >= len) 1372 return 0; 1373 len -= p; 1374 if (len > count) 1375 len = count; 1376 if (copy_to_user(buf, (void *)(tbuf+p), len)) 1377 return -EFAULT; 1378 *ppos += len; 1379 return len; 1380 } 1381 1382 static const struct file_operations use_gss_proxy_ops = { 1383 .open = nonseekable_open, 1384 .write = write_gssp, 1385 .read = read_gssp, 1386 }; 1387 1388 static int create_use_gss_proxy_proc_entry(struct net *net) 1389 { 1390 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1391 struct proc_dir_entry **p = &sn->use_gssp_proc; 1392 1393 sn->use_gss_proxy = -1; 1394 *p = proc_create_data("use-gss-proxy", S_IFREG|S_IRUSR|S_IWUSR, 1395 sn->proc_net_rpc, 1396 &use_gss_proxy_ops, net); 1397 if (!*p) 1398 return -ENOMEM; 1399 init_gssp_clnt(sn); 1400 return 0; 1401 } 1402 1403 static void destroy_use_gss_proxy_proc_entry(struct net *net) 1404 { 1405 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1406 1407 if (sn->use_gssp_proc) { 1408 remove_proc_entry("use-gss-proxy", sn->proc_net_rpc); 1409 clear_gssp_clnt(sn); 1410 } 1411 } 1412 #else /* CONFIG_PROC_FS */ 1413 1414 static int create_use_gss_proxy_proc_entry(struct net *net) 1415 { 1416 return 0; 1417 } 1418 1419 static void destroy_use_gss_proxy_proc_entry(struct net *net) {} 1420 1421 #endif /* CONFIG_PROC_FS */ 1422 1423 /* 1424 * Accept an rpcsec packet. 1425 * If context establishment, punt to user space 1426 * If data exchange, verify/decrypt 1427 * If context destruction, handle here 1428 * In the context establishment and destruction case we encode 1429 * response here and return SVC_COMPLETE. 1430 */ 1431 static int 1432 svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp) 1433 { 1434 struct kvec *argv = &rqstp->rq_arg.head[0]; 1435 struct kvec *resv = &rqstp->rq_res.head[0]; 1436 u32 crlen; 1437 struct gss_svc_data *svcdata = rqstp->rq_auth_data; 1438 struct rpc_gss_wire_cred *gc; 1439 struct rsc *rsci = NULL; 1440 __be32 *rpcstart; 1441 __be32 *reject_stat = resv->iov_base + resv->iov_len; 1442 int ret; 1443 struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id); 1444 1445 dprintk("RPC: svcauth_gss: argv->iov_len = %zd\n", 1446 argv->iov_len); 1447 1448 *authp = rpc_autherr_badcred; 1449 if (!svcdata) 1450 svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL); 1451 if (!svcdata) 1452 goto auth_err; 1453 rqstp->rq_auth_data = svcdata; 1454 svcdata->verf_start = NULL; 1455 svcdata->rsci = NULL; 1456 gc = &svcdata->clcred; 1457 1458 /* start of rpc packet is 7 u32's back from here: 1459 * xid direction rpcversion prog vers proc flavour 1460 */ 1461 rpcstart = argv->iov_base; 1462 rpcstart -= 7; 1463 1464 /* credential is: 1465 * version(==1), proc(0,1,2,3), seq, service (1,2,3), handle 1466 * at least 5 u32s, and is preceded by length, so that makes 6. 1467 */ 1468 1469 if (argv->iov_len < 5 * 4) 1470 goto auth_err; 1471 crlen = svc_getnl(argv); 1472 if (svc_getnl(argv) != RPC_GSS_VERSION) 1473 goto auth_err; 1474 gc->gc_proc = svc_getnl(argv); 1475 gc->gc_seq = svc_getnl(argv); 1476 gc->gc_svc = svc_getnl(argv); 1477 if (svc_safe_getnetobj(argv, &gc->gc_ctx)) 1478 goto auth_err; 1479 if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4) 1480 goto auth_err; 1481 1482 if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0)) 1483 goto auth_err; 1484 1485 *authp = rpc_autherr_badverf; 1486 switch (gc->gc_proc) { 1487 case RPC_GSS_PROC_INIT: 1488 case RPC_GSS_PROC_CONTINUE_INIT: 1489 if (use_gss_proxy(SVC_NET(rqstp))) 1490 return svcauth_gss_proxy_init(rqstp, gc, authp); 1491 else 1492 return svcauth_gss_legacy_init(rqstp, gc, authp); 1493 case RPC_GSS_PROC_DATA: 1494 case RPC_GSS_PROC_DESTROY: 1495 /* Look up the context, and check the verifier: */ 1496 *authp = rpcsec_gsserr_credproblem; 1497 rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx); 1498 if (!rsci) 1499 goto auth_err; 1500 switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) { 1501 case SVC_OK: 1502 break; 1503 case SVC_DENIED: 1504 goto auth_err; 1505 case SVC_DROP: 1506 goto drop; 1507 } 1508 break; 1509 default: 1510 *authp = rpc_autherr_rejectedcred; 1511 goto auth_err; 1512 } 1513 1514 /* now act upon the command: */ 1515 switch (gc->gc_proc) { 1516 case RPC_GSS_PROC_DESTROY: 1517 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq)) 1518 goto auth_err; 1519 rsci->h.expiry_time = get_seconds(); 1520 set_bit(CACHE_NEGATIVE, &rsci->h.flags); 1521 if (resv->iov_len + 4 > PAGE_SIZE) 1522 goto drop; 1523 svc_putnl(resv, RPC_SUCCESS); 1524 goto complete; 1525 case RPC_GSS_PROC_DATA: 1526 *authp = rpcsec_gsserr_ctxproblem; 1527 svcdata->verf_start = resv->iov_base + resv->iov_len; 1528 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq)) 1529 goto auth_err; 1530 rqstp->rq_cred = rsci->cred; 1531 get_group_info(rsci->cred.cr_group_info); 1532 *authp = rpc_autherr_badcred; 1533 switch (gc->gc_svc) { 1534 case RPC_GSS_SVC_NONE: 1535 break; 1536 case RPC_GSS_SVC_INTEGRITY: 1537 /* placeholders for length and seq. number: */ 1538 svc_putnl(resv, 0); 1539 svc_putnl(resv, 0); 1540 if (unwrap_integ_data(rqstp, &rqstp->rq_arg, 1541 gc->gc_seq, rsci->mechctx)) 1542 goto garbage_args; 1543 break; 1544 case RPC_GSS_SVC_PRIVACY: 1545 /* placeholders for length and seq. number: */ 1546 svc_putnl(resv, 0); 1547 svc_putnl(resv, 0); 1548 if (unwrap_priv_data(rqstp, &rqstp->rq_arg, 1549 gc->gc_seq, rsci->mechctx)) 1550 goto garbage_args; 1551 break; 1552 default: 1553 goto auth_err; 1554 } 1555 svcdata->rsci = rsci; 1556 cache_get(&rsci->h); 1557 rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor( 1558 rsci->mechctx->mech_type, 1559 GSS_C_QOP_DEFAULT, 1560 gc->gc_svc); 1561 ret = SVC_OK; 1562 goto out; 1563 } 1564 garbage_args: 1565 ret = SVC_GARBAGE; 1566 goto out; 1567 auth_err: 1568 /* Restore write pointer to its original value: */ 1569 xdr_ressize_check(rqstp, reject_stat); 1570 ret = SVC_DENIED; 1571 goto out; 1572 complete: 1573 ret = SVC_COMPLETE; 1574 goto out; 1575 drop: 1576 ret = SVC_DROP; 1577 out: 1578 if (rsci) 1579 cache_put(&rsci->h, sn->rsc_cache); 1580 return ret; 1581 } 1582 1583 static __be32 * 1584 svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd) 1585 { 1586 __be32 *p; 1587 u32 verf_len; 1588 1589 p = gsd->verf_start; 1590 gsd->verf_start = NULL; 1591 1592 /* If the reply stat is nonzero, don't wrap: */ 1593 if (*(p-1) != rpc_success) 1594 return NULL; 1595 /* Skip the verifier: */ 1596 p += 1; 1597 verf_len = ntohl(*p++); 1598 p += XDR_QUADLEN(verf_len); 1599 /* move accept_stat to right place: */ 1600 memcpy(p, p + 2, 4); 1601 /* Also don't wrap if the accept stat is nonzero: */ 1602 if (*p != rpc_success) { 1603 resbuf->head[0].iov_len -= 2 * 4; 1604 return NULL; 1605 } 1606 p++; 1607 return p; 1608 } 1609 1610 static inline int 1611 svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp) 1612 { 1613 struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data; 1614 struct rpc_gss_wire_cred *gc = &gsd->clcred; 1615 struct xdr_buf *resbuf = &rqstp->rq_res; 1616 struct xdr_buf integ_buf; 1617 struct xdr_netobj mic; 1618 struct kvec *resv; 1619 __be32 *p; 1620 int integ_offset, integ_len; 1621 int stat = -EINVAL; 1622 1623 p = svcauth_gss_prepare_to_wrap(resbuf, gsd); 1624 if (p == NULL) 1625 goto out; 1626 integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base; 1627 integ_len = resbuf->len - integ_offset; 1628 BUG_ON(integ_len % 4); 1629 *p++ = htonl(integ_len); 1630 *p++ = htonl(gc->gc_seq); 1631 if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, 1632 integ_len)) 1633 BUG(); 1634 if (resbuf->tail[0].iov_base == NULL) { 1635 if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE) 1636 goto out_err; 1637 resbuf->tail[0].iov_base = resbuf->head[0].iov_base 1638 + resbuf->head[0].iov_len; 1639 resbuf->tail[0].iov_len = 0; 1640 resv = &resbuf->tail[0]; 1641 } else { 1642 resv = &resbuf->tail[0]; 1643 } 1644 mic.data = (u8 *)resv->iov_base + resv->iov_len + 4; 1645 if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic)) 1646 goto out_err; 1647 svc_putnl(resv, mic.len); 1648 memset(mic.data + mic.len, 0, 1649 round_up_to_quad(mic.len) - mic.len); 1650 resv->iov_len += XDR_QUADLEN(mic.len) << 2; 1651 /* not strictly required: */ 1652 resbuf->len += XDR_QUADLEN(mic.len) << 2; 1653 BUG_ON(resv->iov_len > PAGE_SIZE); 1654 out: 1655 stat = 0; 1656 out_err: 1657 return stat; 1658 } 1659 1660 static inline int 1661 svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp) 1662 { 1663 struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data; 1664 struct rpc_gss_wire_cred *gc = &gsd->clcred; 1665 struct xdr_buf *resbuf = &rqstp->rq_res; 1666 struct page **inpages = NULL; 1667 __be32 *p, *len; 1668 int offset; 1669 int pad; 1670 1671 p = svcauth_gss_prepare_to_wrap(resbuf, gsd); 1672 if (p == NULL) 1673 return 0; 1674 len = p++; 1675 offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base; 1676 *p++ = htonl(gc->gc_seq); 1677 inpages = resbuf->pages; 1678 /* XXX: Would be better to write some xdr helper functions for 1679 * nfs{2,3,4}xdr.c that place the data right, instead of copying: */ 1680 1681 /* 1682 * If there is currently tail data, make sure there is 1683 * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in 1684 * the page, and move the current tail data such that 1685 * there is RPC_MAX_AUTH_SIZE slack space available in 1686 * both the head and tail. 1687 */ 1688 if (resbuf->tail[0].iov_base) { 1689 BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base 1690 + PAGE_SIZE); 1691 BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base); 1692 if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len 1693 + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE) 1694 return -ENOMEM; 1695 memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE, 1696 resbuf->tail[0].iov_base, 1697 resbuf->tail[0].iov_len); 1698 resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE; 1699 } 1700 /* 1701 * If there is no current tail data, make sure there is 1702 * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the 1703 * allotted page, and set up tail information such that there 1704 * is RPC_MAX_AUTH_SIZE slack space available in both the 1705 * head and tail. 1706 */ 1707 if (resbuf->tail[0].iov_base == NULL) { 1708 if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE) 1709 return -ENOMEM; 1710 resbuf->tail[0].iov_base = resbuf->head[0].iov_base 1711 + resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE; 1712 resbuf->tail[0].iov_len = 0; 1713 } 1714 if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages)) 1715 return -ENOMEM; 1716 *len = htonl(resbuf->len - offset); 1717 pad = 3 - ((resbuf->len - offset - 1)&3); 1718 p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len); 1719 memset(p, 0, pad); 1720 resbuf->tail[0].iov_len += pad; 1721 resbuf->len += pad; 1722 return 0; 1723 } 1724 1725 static int 1726 svcauth_gss_release(struct svc_rqst *rqstp) 1727 { 1728 struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data; 1729 struct rpc_gss_wire_cred *gc = &gsd->clcred; 1730 struct xdr_buf *resbuf = &rqstp->rq_res; 1731 int stat = -EINVAL; 1732 struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id); 1733 1734 if (gc->gc_proc != RPC_GSS_PROC_DATA) 1735 goto out; 1736 /* Release can be called twice, but we only wrap once. */ 1737 if (gsd->verf_start == NULL) 1738 goto out; 1739 /* normally not set till svc_send, but we need it here: */ 1740 /* XXX: what for? Do we mess it up the moment we call svc_putu32 1741 * or whatever? */ 1742 resbuf->len = total_buf_len(resbuf); 1743 switch (gc->gc_svc) { 1744 case RPC_GSS_SVC_NONE: 1745 break; 1746 case RPC_GSS_SVC_INTEGRITY: 1747 stat = svcauth_gss_wrap_resp_integ(rqstp); 1748 if (stat) 1749 goto out_err; 1750 break; 1751 case RPC_GSS_SVC_PRIVACY: 1752 stat = svcauth_gss_wrap_resp_priv(rqstp); 1753 if (stat) 1754 goto out_err; 1755 break; 1756 /* 1757 * For any other gc_svc value, svcauth_gss_accept() already set 1758 * the auth_error appropriately; just fall through: 1759 */ 1760 } 1761 1762 out: 1763 stat = 0; 1764 out_err: 1765 if (rqstp->rq_client) 1766 auth_domain_put(rqstp->rq_client); 1767 rqstp->rq_client = NULL; 1768 if (rqstp->rq_gssclient) 1769 auth_domain_put(rqstp->rq_gssclient); 1770 rqstp->rq_gssclient = NULL; 1771 if (rqstp->rq_cred.cr_group_info) 1772 put_group_info(rqstp->rq_cred.cr_group_info); 1773 rqstp->rq_cred.cr_group_info = NULL; 1774 if (gsd->rsci) 1775 cache_put(&gsd->rsci->h, sn->rsc_cache); 1776 gsd->rsci = NULL; 1777 1778 return stat; 1779 } 1780 1781 static void 1782 svcauth_gss_domain_release(struct auth_domain *dom) 1783 { 1784 struct gss_domain *gd = container_of(dom, struct gss_domain, h); 1785 1786 kfree(dom->name); 1787 kfree(gd); 1788 } 1789 1790 static struct auth_ops svcauthops_gss = { 1791 .name = "rpcsec_gss", 1792 .owner = THIS_MODULE, 1793 .flavour = RPC_AUTH_GSS, 1794 .accept = svcauth_gss_accept, 1795 .release = svcauth_gss_release, 1796 .domain_release = svcauth_gss_domain_release, 1797 .set_client = svcauth_gss_set_client, 1798 }; 1799 1800 static int rsi_cache_create_net(struct net *net) 1801 { 1802 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1803 struct cache_detail *cd; 1804 int err; 1805 1806 cd = cache_create_net(&rsi_cache_template, net); 1807 if (IS_ERR(cd)) 1808 return PTR_ERR(cd); 1809 err = cache_register_net(cd, net); 1810 if (err) { 1811 cache_destroy_net(cd, net); 1812 return err; 1813 } 1814 sn->rsi_cache = cd; 1815 return 0; 1816 } 1817 1818 static void rsi_cache_destroy_net(struct net *net) 1819 { 1820 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1821 struct cache_detail *cd = sn->rsi_cache; 1822 1823 sn->rsi_cache = NULL; 1824 cache_purge(cd); 1825 cache_unregister_net(cd, net); 1826 cache_destroy_net(cd, net); 1827 } 1828 1829 static int rsc_cache_create_net(struct net *net) 1830 { 1831 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1832 struct cache_detail *cd; 1833 int err; 1834 1835 cd = cache_create_net(&rsc_cache_template, net); 1836 if (IS_ERR(cd)) 1837 return PTR_ERR(cd); 1838 err = cache_register_net(cd, net); 1839 if (err) { 1840 cache_destroy_net(cd, net); 1841 return err; 1842 } 1843 sn->rsc_cache = cd; 1844 return 0; 1845 } 1846 1847 static void rsc_cache_destroy_net(struct net *net) 1848 { 1849 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 1850 struct cache_detail *cd = sn->rsc_cache; 1851 1852 sn->rsc_cache = NULL; 1853 cache_purge(cd); 1854 cache_unregister_net(cd, net); 1855 cache_destroy_net(cd, net); 1856 } 1857 1858 int 1859 gss_svc_init_net(struct net *net) 1860 { 1861 int rv; 1862 1863 rv = rsc_cache_create_net(net); 1864 if (rv) 1865 return rv; 1866 rv = rsi_cache_create_net(net); 1867 if (rv) 1868 goto out1; 1869 rv = create_use_gss_proxy_proc_entry(net); 1870 if (rv) 1871 goto out2; 1872 return 0; 1873 out2: 1874 destroy_use_gss_proxy_proc_entry(net); 1875 out1: 1876 rsc_cache_destroy_net(net); 1877 return rv; 1878 } 1879 1880 void 1881 gss_svc_shutdown_net(struct net *net) 1882 { 1883 destroy_use_gss_proxy_proc_entry(net); 1884 rsi_cache_destroy_net(net); 1885 rsc_cache_destroy_net(net); 1886 } 1887 1888 int 1889 gss_svc_init(void) 1890 { 1891 return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss); 1892 } 1893 1894 void 1895 gss_svc_shutdown(void) 1896 { 1897 svc_auth_unregister(RPC_AUTH_GSS); 1898 } 1899