1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C)2002 USAGI/WIDE Project 4 * 5 * Authors 6 * 7 * Mitsuru KANDA @USAGI : IPv6 Support 8 * Kazunori MIYAZAWA @USAGI : 9 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 10 * 11 * This file is derived from net/ipv4/ah.c. 12 */ 13 14 #define pr_fmt(fmt) "IPv6: " fmt 15 16 #include <crypto/algapi.h> 17 #include <crypto/hash.h> 18 #include <linux/module.h> 19 #include <linux/slab.h> 20 #include <net/ip.h> 21 #include <net/ah.h> 22 #include <linux/crypto.h> 23 #include <linux/pfkeyv2.h> 24 #include <linux/string.h> 25 #include <linux/scatterlist.h> 26 #include <net/ip6_route.h> 27 #include <net/icmp.h> 28 #include <net/ipv6.h> 29 #include <net/protocol.h> 30 #include <net/xfrm.h> 31 32 #define IPV6HDR_BASELEN 8 33 34 struct tmp_ext { 35 #if IS_ENABLED(CONFIG_IPV6_MIP6) 36 struct in6_addr saddr; 37 #endif 38 struct in6_addr daddr; 39 char hdrs[]; 40 }; 41 42 struct ah_skb_cb { 43 struct xfrm_skb_cb xfrm; 44 void *tmp; 45 }; 46 47 #define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0])) 48 49 static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags, 50 unsigned int size) 51 { 52 unsigned int len; 53 54 len = size + crypto_ahash_digestsize(ahash) + 55 (crypto_ahash_alignmask(ahash) & 56 ~(crypto_tfm_ctx_alignment() - 1)); 57 58 len = ALIGN(len, crypto_tfm_ctx_alignment()); 59 60 len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); 61 len = ALIGN(len, __alignof__(struct scatterlist)); 62 63 len += sizeof(struct scatterlist) * nfrags; 64 65 return kmalloc(len, GFP_ATOMIC); 66 } 67 68 static inline struct tmp_ext *ah_tmp_ext(void *base) 69 { 70 return base + IPV6HDR_BASELEN; 71 } 72 73 static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset) 74 { 75 return tmp + offset; 76 } 77 78 static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp, 79 unsigned int offset) 80 { 81 return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1); 82 } 83 84 static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, 85 u8 *icv) 86 { 87 struct ahash_request *req; 88 89 req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), 90 crypto_tfm_ctx_alignment()); 91 92 ahash_request_set_tfm(req, ahash); 93 94 return req; 95 } 96 97 static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, 98 struct ahash_request *req) 99 { 100 return (void *)ALIGN((unsigned long)(req + 1) + 101 crypto_ahash_reqsize(ahash), 102 __alignof__(struct scatterlist)); 103 } 104 105 static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr) 106 { 107 u8 *opt = (u8 *)opthdr; 108 int len = ipv6_optlen(opthdr); 109 int off = 0; 110 int optlen = 0; 111 112 off += 2; 113 len -= 2; 114 115 while (len > 0) { 116 117 switch (opt[off]) { 118 119 case IPV6_TLV_PAD1: 120 optlen = 1; 121 break; 122 default: 123 if (len < 2) 124 goto bad; 125 optlen = opt[off+1]+2; 126 if (len < optlen) 127 goto bad; 128 if (opt[off] & 0x20) 129 memset(&opt[off+2], 0, opt[off+1]); 130 break; 131 } 132 133 off += optlen; 134 len -= optlen; 135 } 136 if (len == 0) 137 return true; 138 139 bad: 140 return false; 141 } 142 143 #if IS_ENABLED(CONFIG_IPV6_MIP6) 144 /** 145 * ipv6_rearrange_destopt - rearrange IPv6 destination options header 146 * @iph: IPv6 header 147 * @destopt: destionation options header 148 */ 149 static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) 150 { 151 u8 *opt = (u8 *)destopt; 152 int len = ipv6_optlen(destopt); 153 int off = 0; 154 int optlen = 0; 155 156 off += 2; 157 len -= 2; 158 159 while (len > 0) { 160 161 switch (opt[off]) { 162 163 case IPV6_TLV_PAD1: 164 optlen = 1; 165 break; 166 default: 167 if (len < 2) 168 goto bad; 169 optlen = opt[off+1]+2; 170 if (len < optlen) 171 goto bad; 172 173 /* Rearrange the source address in @iph and the 174 * addresses in home address option for final source. 175 * See 11.3.2 of RFC 3775 for details. 176 */ 177 if (opt[off] == IPV6_TLV_HAO) { 178 struct ipv6_destopt_hao *hao; 179 180 hao = (struct ipv6_destopt_hao *)&opt[off]; 181 if (hao->length != sizeof(hao->addr)) { 182 net_warn_ratelimited("destopt hao: invalid header length: %u\n", 183 hao->length); 184 goto bad; 185 } 186 swap(hao->addr, iph->saddr); 187 } 188 break; 189 } 190 191 off += optlen; 192 len -= optlen; 193 } 194 /* Note: ok if len == 0 */ 195 bad: 196 return; 197 } 198 #else 199 static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} 200 #endif 201 202 /** 203 * ipv6_rearrange_rthdr - rearrange IPv6 routing header 204 * @iph: IPv6 header 205 * @rthdr: routing header 206 * 207 * Rearrange the destination address in @iph and the addresses in @rthdr 208 * so that they appear in the order they will at the final destination. 209 * See Appendix A2 of RFC 2402 for details. 210 */ 211 static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) 212 { 213 int segments, segments_left; 214 struct in6_addr *addrs; 215 struct in6_addr final_addr; 216 217 segments_left = rthdr->segments_left; 218 if (segments_left == 0) 219 return; 220 rthdr->segments_left = 0; 221 222 /* The value of rthdr->hdrlen has been verified either by the system 223 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming 224 * packets. So we can assume that it is even and that segments is 225 * greater than or equal to segments_left. 226 * 227 * For the same reason we can assume that this option is of type 0. 228 */ 229 segments = rthdr->hdrlen >> 1; 230 231 addrs = ((struct rt0_hdr *)rthdr)->addr; 232 final_addr = addrs[segments - 1]; 233 234 addrs += segments - segments_left; 235 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); 236 237 addrs[0] = iph->daddr; 238 iph->daddr = final_addr; 239 } 240 241 static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) 242 { 243 union { 244 struct ipv6hdr *iph; 245 struct ipv6_opt_hdr *opth; 246 struct ipv6_rt_hdr *rth; 247 char *raw; 248 } exthdr = { .iph = iph }; 249 char *end = exthdr.raw + len; 250 int nexthdr = iph->nexthdr; 251 252 exthdr.iph++; 253 254 while (exthdr.raw < end) { 255 switch (nexthdr) { 256 case NEXTHDR_DEST: 257 if (dir == XFRM_POLICY_OUT) 258 ipv6_rearrange_destopt(iph, exthdr.opth); 259 fallthrough; 260 case NEXTHDR_HOP: 261 if (!zero_out_mutable_opts(exthdr.opth)) { 262 net_dbg_ratelimited("overrun %sopts\n", 263 nexthdr == NEXTHDR_HOP ? 264 "hop" : "dest"); 265 return -EINVAL; 266 } 267 break; 268 269 case NEXTHDR_ROUTING: 270 ipv6_rearrange_rthdr(iph, exthdr.rth); 271 break; 272 273 default: 274 return 0; 275 } 276 277 nexthdr = exthdr.opth->nexthdr; 278 exthdr.raw += ipv6_optlen(exthdr.opth); 279 } 280 281 return 0; 282 } 283 284 static void ah6_output_done(struct crypto_async_request *base, int err) 285 { 286 int extlen; 287 u8 *iph_base; 288 u8 *icv; 289 struct sk_buff *skb = base->data; 290 struct xfrm_state *x = skb_dst(skb)->xfrm; 291 struct ah_data *ahp = x->data; 292 struct ipv6hdr *top_iph = ipv6_hdr(skb); 293 struct ip_auth_hdr *ah = ip_auth_hdr(skb); 294 struct tmp_ext *iph_ext; 295 296 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); 297 if (extlen) 298 extlen += sizeof(*iph_ext); 299 300 iph_base = AH_SKB_CB(skb)->tmp; 301 iph_ext = ah_tmp_ext(iph_base); 302 icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); 303 304 memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 305 memcpy(top_iph, iph_base, IPV6HDR_BASELEN); 306 307 if (extlen) { 308 #if IS_ENABLED(CONFIG_IPV6_MIP6) 309 memcpy(&top_iph->saddr, iph_ext, extlen); 310 #else 311 memcpy(&top_iph->daddr, iph_ext, extlen); 312 #endif 313 } 314 315 kfree(AH_SKB_CB(skb)->tmp); 316 xfrm_output_resume(skb->sk, skb, err); 317 } 318 319 static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) 320 { 321 int err; 322 int nfrags; 323 int extlen; 324 u8 *iph_base; 325 u8 *icv; 326 u8 nexthdr; 327 struct sk_buff *trailer; 328 struct crypto_ahash *ahash; 329 struct ahash_request *req; 330 struct scatterlist *sg; 331 struct ipv6hdr *top_iph; 332 struct ip_auth_hdr *ah; 333 struct ah_data *ahp; 334 struct tmp_ext *iph_ext; 335 int seqhi_len = 0; 336 __be32 *seqhi; 337 int sglists = 0; 338 struct scatterlist *seqhisg; 339 340 ahp = x->data; 341 ahash = ahp->ahash; 342 343 err = skb_cow_data(skb, 0, &trailer); 344 if (err < 0) 345 goto out; 346 nfrags = err; 347 348 skb_push(skb, -skb_network_offset(skb)); 349 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); 350 if (extlen) 351 extlen += sizeof(*iph_ext); 352 353 if (x->props.flags & XFRM_STATE_ESN) { 354 sglists = 1; 355 seqhi_len = sizeof(*seqhi); 356 } 357 err = -ENOMEM; 358 iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN + 359 extlen + seqhi_len); 360 if (!iph_base) 361 goto out; 362 363 iph_ext = ah_tmp_ext(iph_base); 364 seqhi = (__be32 *)((char *)iph_ext + extlen); 365 icv = ah_tmp_icv(ahash, seqhi, seqhi_len); 366 req = ah_tmp_req(ahash, icv); 367 sg = ah_req_sg(ahash, req); 368 seqhisg = sg + nfrags; 369 370 ah = ip_auth_hdr(skb); 371 memset(ah->auth_data, 0, ahp->icv_trunc_len); 372 373 top_iph = ipv6_hdr(skb); 374 top_iph->payload_len = htons(skb->len - sizeof(*top_iph)); 375 376 nexthdr = *skb_mac_header(skb); 377 *skb_mac_header(skb) = IPPROTO_AH; 378 379 /* When there are no extension headers, we only need to save the first 380 * 8 bytes of the base IP header. 381 */ 382 memcpy(iph_base, top_iph, IPV6HDR_BASELEN); 383 384 if (extlen) { 385 #if IS_ENABLED(CONFIG_IPV6_MIP6) 386 memcpy(iph_ext, &top_iph->saddr, extlen); 387 #else 388 memcpy(iph_ext, &top_iph->daddr, extlen); 389 #endif 390 err = ipv6_clear_mutable_options(top_iph, 391 extlen - sizeof(*iph_ext) + 392 sizeof(*top_iph), 393 XFRM_POLICY_OUT); 394 if (err) 395 goto out_free; 396 } 397 398 ah->nexthdr = nexthdr; 399 400 top_iph->priority = 0; 401 top_iph->flow_lbl[0] = 0; 402 top_iph->flow_lbl[1] = 0; 403 top_iph->flow_lbl[2] = 0; 404 top_iph->hop_limit = 0; 405 406 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; 407 408 ah->reserved = 0; 409 ah->spi = x->id.spi; 410 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 411 412 sg_init_table(sg, nfrags + sglists); 413 err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); 414 if (unlikely(err < 0)) 415 goto out_free; 416 417 if (x->props.flags & XFRM_STATE_ESN) { 418 /* Attach seqhi sg right after packet payload */ 419 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); 420 sg_set_buf(seqhisg, seqhi, seqhi_len); 421 } 422 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); 423 ahash_request_set_callback(req, 0, ah6_output_done, skb); 424 425 AH_SKB_CB(skb)->tmp = iph_base; 426 427 err = crypto_ahash_digest(req); 428 if (err) { 429 if (err == -EINPROGRESS) 430 goto out; 431 432 if (err == -ENOSPC) 433 err = NET_XMIT_DROP; 434 goto out_free; 435 } 436 437 memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 438 memcpy(top_iph, iph_base, IPV6HDR_BASELEN); 439 440 if (extlen) { 441 #if IS_ENABLED(CONFIG_IPV6_MIP6) 442 memcpy(&top_iph->saddr, iph_ext, extlen); 443 #else 444 memcpy(&top_iph->daddr, iph_ext, extlen); 445 #endif 446 } 447 448 out_free: 449 kfree(iph_base); 450 out: 451 return err; 452 } 453 454 static void ah6_input_done(struct crypto_async_request *base, int err) 455 { 456 u8 *auth_data; 457 u8 *icv; 458 u8 *work_iph; 459 struct sk_buff *skb = base->data; 460 struct xfrm_state *x = xfrm_input_state(skb); 461 struct ah_data *ahp = x->data; 462 struct ip_auth_hdr *ah = ip_auth_hdr(skb); 463 int hdr_len = skb_network_header_len(skb); 464 int ah_hlen = ipv6_authlen(ah); 465 466 if (err) 467 goto out; 468 469 work_iph = AH_SKB_CB(skb)->tmp; 470 auth_data = ah_tmp_auth(work_iph, hdr_len); 471 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); 472 473 err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; 474 if (err) 475 goto out; 476 477 err = ah->nexthdr; 478 479 skb->network_header += ah_hlen; 480 memcpy(skb_network_header(skb), work_iph, hdr_len); 481 __skb_pull(skb, ah_hlen + hdr_len); 482 if (x->props.mode == XFRM_MODE_TUNNEL) 483 skb_reset_transport_header(skb); 484 else 485 skb_set_transport_header(skb, -hdr_len); 486 out: 487 kfree(AH_SKB_CB(skb)->tmp); 488 xfrm_input_resume(skb, err); 489 } 490 491 492 493 static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) 494 { 495 /* 496 * Before process AH 497 * [IPv6][Ext1][Ext2][AH][Dest][Payload] 498 * |<-------------->| hdr_len 499 * 500 * To erase AH: 501 * Keeping copy of cleared headers. After AH processing, 502 * Moving the pointer of skb->network_header by using skb_pull as long 503 * as AH header length. Then copy back the copy as long as hdr_len 504 * If destination header following AH exists, copy it into after [Ext2]. 505 * 506 * |<>|[IPv6][Ext1][Ext2][Dest][Payload] 507 * There is offset of AH before IPv6 header after the process. 508 */ 509 510 u8 *auth_data; 511 u8 *icv; 512 u8 *work_iph; 513 struct sk_buff *trailer; 514 struct crypto_ahash *ahash; 515 struct ahash_request *req; 516 struct scatterlist *sg; 517 struct ip_auth_hdr *ah; 518 struct ipv6hdr *ip6h; 519 struct ah_data *ahp; 520 u16 hdr_len; 521 u16 ah_hlen; 522 int nexthdr; 523 int nfrags; 524 int err = -ENOMEM; 525 int seqhi_len = 0; 526 __be32 *seqhi; 527 int sglists = 0; 528 struct scatterlist *seqhisg; 529 530 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) 531 goto out; 532 533 /* We are going to _remove_ AH header to keep sockets happy, 534 * so... Later this can change. */ 535 if (skb_unclone(skb, GFP_ATOMIC)) 536 goto out; 537 538 skb->ip_summed = CHECKSUM_NONE; 539 540 hdr_len = skb_network_header_len(skb); 541 ah = (struct ip_auth_hdr *)skb->data; 542 ahp = x->data; 543 ahash = ahp->ahash; 544 545 nexthdr = ah->nexthdr; 546 ah_hlen = ipv6_authlen(ah); 547 548 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && 549 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) 550 goto out; 551 552 if (!pskb_may_pull(skb, ah_hlen)) 553 goto out; 554 555 err = skb_cow_data(skb, 0, &trailer); 556 if (err < 0) 557 goto out; 558 nfrags = err; 559 560 ah = (struct ip_auth_hdr *)skb->data; 561 ip6h = ipv6_hdr(skb); 562 563 skb_push(skb, hdr_len); 564 565 if (x->props.flags & XFRM_STATE_ESN) { 566 sglists = 1; 567 seqhi_len = sizeof(*seqhi); 568 } 569 570 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len + 571 ahp->icv_trunc_len + seqhi_len); 572 if (!work_iph) { 573 err = -ENOMEM; 574 goto out; 575 } 576 577 auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len); 578 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len); 579 icv = ah_tmp_icv(ahash, seqhi, seqhi_len); 580 req = ah_tmp_req(ahash, icv); 581 sg = ah_req_sg(ahash, req); 582 seqhisg = sg + nfrags; 583 584 memcpy(work_iph, ip6h, hdr_len); 585 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); 586 memset(ah->auth_data, 0, ahp->icv_trunc_len); 587 588 err = ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN); 589 if (err) 590 goto out_free; 591 592 ip6h->priority = 0; 593 ip6h->flow_lbl[0] = 0; 594 ip6h->flow_lbl[1] = 0; 595 ip6h->flow_lbl[2] = 0; 596 ip6h->hop_limit = 0; 597 598 sg_init_table(sg, nfrags + sglists); 599 err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); 600 if (unlikely(err < 0)) 601 goto out_free; 602 603 if (x->props.flags & XFRM_STATE_ESN) { 604 /* Attach seqhi sg right after packet payload */ 605 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; 606 sg_set_buf(seqhisg, seqhi, seqhi_len); 607 } 608 609 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); 610 ahash_request_set_callback(req, 0, ah6_input_done, skb); 611 612 AH_SKB_CB(skb)->tmp = work_iph; 613 614 err = crypto_ahash_digest(req); 615 if (err) { 616 if (err == -EINPROGRESS) 617 goto out; 618 619 goto out_free; 620 } 621 622 err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; 623 if (err) 624 goto out_free; 625 626 skb->network_header += ah_hlen; 627 memcpy(skb_network_header(skb), work_iph, hdr_len); 628 __skb_pull(skb, ah_hlen + hdr_len); 629 630 if (x->props.mode == XFRM_MODE_TUNNEL) 631 skb_reset_transport_header(skb); 632 else 633 skb_set_transport_header(skb, -hdr_len); 634 635 err = nexthdr; 636 637 out_free: 638 kfree(work_iph); 639 out: 640 return err; 641 } 642 643 static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 644 u8 type, u8 code, int offset, __be32 info) 645 { 646 struct net *net = dev_net(skb->dev); 647 struct ipv6hdr *iph = (struct ipv6hdr *)skb->data; 648 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset); 649 struct xfrm_state *x; 650 651 if (type != ICMPV6_PKT_TOOBIG && 652 type != NDISC_REDIRECT) 653 return 0; 654 655 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); 656 if (!x) 657 return 0; 658 659 if (type == NDISC_REDIRECT) 660 ip6_redirect(skb, net, skb->dev->ifindex, 0, 661 sock_net_uid(net, NULL)); 662 else 663 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 664 xfrm_state_put(x); 665 666 return 0; 667 } 668 669 static int ah6_init_state(struct xfrm_state *x) 670 { 671 struct ah_data *ahp = NULL; 672 struct xfrm_algo_desc *aalg_desc; 673 struct crypto_ahash *ahash; 674 675 if (!x->aalg) 676 goto error; 677 678 if (x->encap) 679 goto error; 680 681 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); 682 if (!ahp) 683 return -ENOMEM; 684 685 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); 686 if (IS_ERR(ahash)) 687 goto error; 688 689 ahp->ahash = ahash; 690 if (crypto_ahash_setkey(ahash, x->aalg->alg_key, 691 (x->aalg->alg_key_len + 7) / 8)) 692 goto error; 693 694 /* 695 * Lookup the algorithm description maintained by xfrm_algo, 696 * verify crypto transform properties, and store information 697 * we need for AH processing. This lookup cannot fail here 698 * after a successful crypto_alloc_hash(). 699 */ 700 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 701 BUG_ON(!aalg_desc); 702 703 if (aalg_desc->uinfo.auth.icv_fullbits/8 != 704 crypto_ahash_digestsize(ahash)) { 705 pr_info("AH: %s digestsize %u != %u\n", 706 x->aalg->alg_name, crypto_ahash_digestsize(ahash), 707 aalg_desc->uinfo.auth.icv_fullbits/8); 708 goto error; 709 } 710 711 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; 712 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; 713 714 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + 715 ahp->icv_trunc_len); 716 switch (x->props.mode) { 717 case XFRM_MODE_BEET: 718 case XFRM_MODE_TRANSPORT: 719 break; 720 case XFRM_MODE_TUNNEL: 721 x->props.header_len += sizeof(struct ipv6hdr); 722 break; 723 default: 724 goto error; 725 } 726 x->data = ahp; 727 728 return 0; 729 730 error: 731 if (ahp) { 732 crypto_free_ahash(ahp->ahash); 733 kfree(ahp); 734 } 735 return -EINVAL; 736 } 737 738 static void ah6_destroy(struct xfrm_state *x) 739 { 740 struct ah_data *ahp = x->data; 741 742 if (!ahp) 743 return; 744 745 crypto_free_ahash(ahp->ahash); 746 kfree(ahp); 747 } 748 749 static int ah6_rcv_cb(struct sk_buff *skb, int err) 750 { 751 return 0; 752 } 753 754 static const struct xfrm_type ah6_type = { 755 .owner = THIS_MODULE, 756 .proto = IPPROTO_AH, 757 .flags = XFRM_TYPE_REPLAY_PROT, 758 .init_state = ah6_init_state, 759 .destructor = ah6_destroy, 760 .input = ah6_input, 761 .output = ah6_output, 762 }; 763 764 static struct xfrm6_protocol ah6_protocol = { 765 .handler = xfrm6_rcv, 766 .input_handler = xfrm_input, 767 .cb_handler = ah6_rcv_cb, 768 .err_handler = ah6_err, 769 .priority = 0, 770 }; 771 772 static int __init ah6_init(void) 773 { 774 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) { 775 pr_info("%s: can't add xfrm type\n", __func__); 776 return -EAGAIN; 777 } 778 779 if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) { 780 pr_info("%s: can't add protocol\n", __func__); 781 xfrm_unregister_type(&ah6_type, AF_INET6); 782 return -EAGAIN; 783 } 784 785 return 0; 786 } 787 788 static void __exit ah6_fini(void) 789 { 790 if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0) 791 pr_info("%s: can't remove protocol\n", __func__); 792 793 xfrm_unregister_type(&ah6_type, AF_INET6); 794 } 795 796 module_init(ah6_init); 797 module_exit(ah6_fini); 798 799 MODULE_LICENSE("GPL"); 800 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH); 801