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 in6_addr final_addr; 179 struct ipv6_destopt_hao *hao; 180 181 hao = (struct ipv6_destopt_hao *)&opt[off]; 182 if (hao->length != sizeof(hao->addr)) { 183 net_warn_ratelimited("destopt hao: invalid header length: %u\n", 184 hao->length); 185 goto bad; 186 } 187 final_addr = hao->addr; 188 hao->addr = iph->saddr; 189 iph->saddr = final_addr; 190 } 191 break; 192 } 193 194 off += optlen; 195 len -= optlen; 196 } 197 /* Note: ok if len == 0 */ 198 bad: 199 return; 200 } 201 #else 202 static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} 203 #endif 204 205 /** 206 * ipv6_rearrange_rthdr - rearrange IPv6 routing header 207 * @iph: IPv6 header 208 * @rthdr: routing header 209 * 210 * Rearrange the destination address in @iph and the addresses in @rthdr 211 * so that they appear in the order they will at the final destination. 212 * See Appendix A2 of RFC 2402 for details. 213 */ 214 static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) 215 { 216 int segments, segments_left; 217 struct in6_addr *addrs; 218 struct in6_addr final_addr; 219 220 segments_left = rthdr->segments_left; 221 if (segments_left == 0) 222 return; 223 rthdr->segments_left = 0; 224 225 /* The value of rthdr->hdrlen has been verified either by the system 226 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming 227 * packets. So we can assume that it is even and that segments is 228 * greater than or equal to segments_left. 229 * 230 * For the same reason we can assume that this option is of type 0. 231 */ 232 segments = rthdr->hdrlen >> 1; 233 234 addrs = ((struct rt0_hdr *)rthdr)->addr; 235 final_addr = addrs[segments - 1]; 236 237 addrs += segments - segments_left; 238 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); 239 240 addrs[0] = iph->daddr; 241 iph->daddr = final_addr; 242 } 243 244 static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) 245 { 246 union { 247 struct ipv6hdr *iph; 248 struct ipv6_opt_hdr *opth; 249 struct ipv6_rt_hdr *rth; 250 char *raw; 251 } exthdr = { .iph = iph }; 252 char *end = exthdr.raw + len; 253 int nexthdr = iph->nexthdr; 254 255 exthdr.iph++; 256 257 while (exthdr.raw < end) { 258 switch (nexthdr) { 259 case NEXTHDR_DEST: 260 if (dir == XFRM_POLICY_OUT) 261 ipv6_rearrange_destopt(iph, exthdr.opth); 262 fallthrough; 263 case NEXTHDR_HOP: 264 if (!zero_out_mutable_opts(exthdr.opth)) { 265 net_dbg_ratelimited("overrun %sopts\n", 266 nexthdr == NEXTHDR_HOP ? 267 "hop" : "dest"); 268 return -EINVAL; 269 } 270 break; 271 272 case NEXTHDR_ROUTING: 273 ipv6_rearrange_rthdr(iph, exthdr.rth); 274 break; 275 276 default: 277 return 0; 278 } 279 280 nexthdr = exthdr.opth->nexthdr; 281 exthdr.raw += ipv6_optlen(exthdr.opth); 282 } 283 284 return 0; 285 } 286 287 static void ah6_output_done(struct crypto_async_request *base, int err) 288 { 289 int extlen; 290 u8 *iph_base; 291 u8 *icv; 292 struct sk_buff *skb = base->data; 293 struct xfrm_state *x = skb_dst(skb)->xfrm; 294 struct ah_data *ahp = x->data; 295 struct ipv6hdr *top_iph = ipv6_hdr(skb); 296 struct ip_auth_hdr *ah = ip_auth_hdr(skb); 297 struct tmp_ext *iph_ext; 298 299 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); 300 if (extlen) 301 extlen += sizeof(*iph_ext); 302 303 iph_base = AH_SKB_CB(skb)->tmp; 304 iph_ext = ah_tmp_ext(iph_base); 305 icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); 306 307 memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 308 memcpy(top_iph, iph_base, IPV6HDR_BASELEN); 309 310 if (extlen) { 311 #if IS_ENABLED(CONFIG_IPV6_MIP6) 312 memcpy(&top_iph->saddr, iph_ext, extlen); 313 #else 314 memcpy(&top_iph->daddr, iph_ext, extlen); 315 #endif 316 } 317 318 kfree(AH_SKB_CB(skb)->tmp); 319 xfrm_output_resume(skb, err); 320 } 321 322 static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) 323 { 324 int err; 325 int nfrags; 326 int extlen; 327 u8 *iph_base; 328 u8 *icv; 329 u8 nexthdr; 330 struct sk_buff *trailer; 331 struct crypto_ahash *ahash; 332 struct ahash_request *req; 333 struct scatterlist *sg; 334 struct ipv6hdr *top_iph; 335 struct ip_auth_hdr *ah; 336 struct ah_data *ahp; 337 struct tmp_ext *iph_ext; 338 int seqhi_len = 0; 339 __be32 *seqhi; 340 int sglists = 0; 341 struct scatterlist *seqhisg; 342 343 ahp = x->data; 344 ahash = ahp->ahash; 345 346 err = skb_cow_data(skb, 0, &trailer); 347 if (err < 0) 348 goto out; 349 nfrags = err; 350 351 skb_push(skb, -skb_network_offset(skb)); 352 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); 353 if (extlen) 354 extlen += sizeof(*iph_ext); 355 356 if (x->props.flags & XFRM_STATE_ESN) { 357 sglists = 1; 358 seqhi_len = sizeof(*seqhi); 359 } 360 err = -ENOMEM; 361 iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN + 362 extlen + seqhi_len); 363 if (!iph_base) 364 goto out; 365 366 iph_ext = ah_tmp_ext(iph_base); 367 seqhi = (__be32 *)((char *)iph_ext + extlen); 368 icv = ah_tmp_icv(ahash, seqhi, seqhi_len); 369 req = ah_tmp_req(ahash, icv); 370 sg = ah_req_sg(ahash, req); 371 seqhisg = sg + nfrags; 372 373 ah = ip_auth_hdr(skb); 374 memset(ah->auth_data, 0, ahp->icv_trunc_len); 375 376 top_iph = ipv6_hdr(skb); 377 top_iph->payload_len = htons(skb->len - sizeof(*top_iph)); 378 379 nexthdr = *skb_mac_header(skb); 380 *skb_mac_header(skb) = IPPROTO_AH; 381 382 /* When there are no extension headers, we only need to save the first 383 * 8 bytes of the base IP header. 384 */ 385 memcpy(iph_base, top_iph, IPV6HDR_BASELEN); 386 387 if (extlen) { 388 #if IS_ENABLED(CONFIG_IPV6_MIP6) 389 memcpy(iph_ext, &top_iph->saddr, extlen); 390 #else 391 memcpy(iph_ext, &top_iph->daddr, extlen); 392 #endif 393 err = ipv6_clear_mutable_options(top_iph, 394 extlen - sizeof(*iph_ext) + 395 sizeof(*top_iph), 396 XFRM_POLICY_OUT); 397 if (err) 398 goto out_free; 399 } 400 401 ah->nexthdr = nexthdr; 402 403 top_iph->priority = 0; 404 top_iph->flow_lbl[0] = 0; 405 top_iph->flow_lbl[1] = 0; 406 top_iph->flow_lbl[2] = 0; 407 top_iph->hop_limit = 0; 408 409 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; 410 411 ah->reserved = 0; 412 ah->spi = x->id.spi; 413 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 414 415 sg_init_table(sg, nfrags + sglists); 416 err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); 417 if (unlikely(err < 0)) 418 goto out_free; 419 420 if (x->props.flags & XFRM_STATE_ESN) { 421 /* Attach seqhi sg right after packet payload */ 422 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); 423 sg_set_buf(seqhisg, seqhi, seqhi_len); 424 } 425 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); 426 ahash_request_set_callback(req, 0, ah6_output_done, skb); 427 428 AH_SKB_CB(skb)->tmp = iph_base; 429 430 err = crypto_ahash_digest(req); 431 if (err) { 432 if (err == -EINPROGRESS) 433 goto out; 434 435 if (err == -ENOSPC) 436 err = NET_XMIT_DROP; 437 goto out_free; 438 } 439 440 memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 441 memcpy(top_iph, iph_base, IPV6HDR_BASELEN); 442 443 if (extlen) { 444 #if IS_ENABLED(CONFIG_IPV6_MIP6) 445 memcpy(&top_iph->saddr, iph_ext, extlen); 446 #else 447 memcpy(&top_iph->daddr, iph_ext, extlen); 448 #endif 449 } 450 451 out_free: 452 kfree(iph_base); 453 out: 454 return err; 455 } 456 457 static void ah6_input_done(struct crypto_async_request *base, int err) 458 { 459 u8 *auth_data; 460 u8 *icv; 461 u8 *work_iph; 462 struct sk_buff *skb = base->data; 463 struct xfrm_state *x = xfrm_input_state(skb); 464 struct ah_data *ahp = x->data; 465 struct ip_auth_hdr *ah = ip_auth_hdr(skb); 466 int hdr_len = skb_network_header_len(skb); 467 int ah_hlen = ipv6_authlen(ah); 468 469 if (err) 470 goto out; 471 472 work_iph = AH_SKB_CB(skb)->tmp; 473 auth_data = ah_tmp_auth(work_iph, hdr_len); 474 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); 475 476 err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; 477 if (err) 478 goto out; 479 480 err = ah->nexthdr; 481 482 skb->network_header += ah_hlen; 483 memcpy(skb_network_header(skb), work_iph, hdr_len); 484 __skb_pull(skb, ah_hlen + hdr_len); 485 if (x->props.mode == XFRM_MODE_TUNNEL) 486 skb_reset_transport_header(skb); 487 else 488 skb_set_transport_header(skb, -hdr_len); 489 out: 490 kfree(AH_SKB_CB(skb)->tmp); 491 xfrm_input_resume(skb, err); 492 } 493 494 495 496 static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) 497 { 498 /* 499 * Before process AH 500 * [IPv6][Ext1][Ext2][AH][Dest][Payload] 501 * |<-------------->| hdr_len 502 * 503 * To erase AH: 504 * Keeping copy of cleared headers. After AH processing, 505 * Moving the pointer of skb->network_header by using skb_pull as long 506 * as AH header length. Then copy back the copy as long as hdr_len 507 * If destination header following AH exists, copy it into after [Ext2]. 508 * 509 * |<>|[IPv6][Ext1][Ext2][Dest][Payload] 510 * There is offset of AH before IPv6 header after the process. 511 */ 512 513 u8 *auth_data; 514 u8 *icv; 515 u8 *work_iph; 516 struct sk_buff *trailer; 517 struct crypto_ahash *ahash; 518 struct ahash_request *req; 519 struct scatterlist *sg; 520 struct ip_auth_hdr *ah; 521 struct ipv6hdr *ip6h; 522 struct ah_data *ahp; 523 u16 hdr_len; 524 u16 ah_hlen; 525 int nexthdr; 526 int nfrags; 527 int err = -ENOMEM; 528 int seqhi_len = 0; 529 __be32 *seqhi; 530 int sglists = 0; 531 struct scatterlist *seqhisg; 532 533 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) 534 goto out; 535 536 /* We are going to _remove_ AH header to keep sockets happy, 537 * so... Later this can change. */ 538 if (skb_unclone(skb, GFP_ATOMIC)) 539 goto out; 540 541 skb->ip_summed = CHECKSUM_NONE; 542 543 hdr_len = skb_network_header_len(skb); 544 ah = (struct ip_auth_hdr *)skb->data; 545 ahp = x->data; 546 ahash = ahp->ahash; 547 548 nexthdr = ah->nexthdr; 549 ah_hlen = ipv6_authlen(ah); 550 551 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && 552 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) 553 goto out; 554 555 if (!pskb_may_pull(skb, ah_hlen)) 556 goto out; 557 558 err = skb_cow_data(skb, 0, &trailer); 559 if (err < 0) 560 goto out; 561 nfrags = err; 562 563 ah = (struct ip_auth_hdr *)skb->data; 564 ip6h = ipv6_hdr(skb); 565 566 skb_push(skb, hdr_len); 567 568 if (x->props.flags & XFRM_STATE_ESN) { 569 sglists = 1; 570 seqhi_len = sizeof(*seqhi); 571 } 572 573 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len + 574 ahp->icv_trunc_len + seqhi_len); 575 if (!work_iph) { 576 err = -ENOMEM; 577 goto out; 578 } 579 580 auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len); 581 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len); 582 icv = ah_tmp_icv(ahash, seqhi, seqhi_len); 583 req = ah_tmp_req(ahash, icv); 584 sg = ah_req_sg(ahash, req); 585 seqhisg = sg + nfrags; 586 587 memcpy(work_iph, ip6h, hdr_len); 588 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); 589 memset(ah->auth_data, 0, ahp->icv_trunc_len); 590 591 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN)) 592 goto out_free; 593 594 ip6h->priority = 0; 595 ip6h->flow_lbl[0] = 0; 596 ip6h->flow_lbl[1] = 0; 597 ip6h->flow_lbl[2] = 0; 598 ip6h->hop_limit = 0; 599 600 sg_init_table(sg, nfrags + sglists); 601 err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); 602 if (unlikely(err < 0)) 603 goto out_free; 604 605 if (x->props.flags & XFRM_STATE_ESN) { 606 /* Attach seqhi sg right after packet payload */ 607 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; 608 sg_set_buf(seqhisg, seqhi, seqhi_len); 609 } 610 611 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); 612 ahash_request_set_callback(req, 0, ah6_input_done, skb); 613 614 AH_SKB_CB(skb)->tmp = work_iph; 615 616 err = crypto_ahash_digest(req); 617 if (err) { 618 if (err == -EINPROGRESS) 619 goto out; 620 621 goto out_free; 622 } 623 624 err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; 625 if (err) 626 goto out_free; 627 628 skb->network_header += ah_hlen; 629 memcpy(skb_network_header(skb), work_iph, hdr_len); 630 __skb_pull(skb, ah_hlen + hdr_len); 631 632 if (x->props.mode == XFRM_MODE_TUNNEL) 633 skb_reset_transport_header(skb); 634 else 635 skb_set_transport_header(skb, -hdr_len); 636 637 err = nexthdr; 638 639 out_free: 640 kfree(work_iph); 641 out: 642 return err; 643 } 644 645 static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 646 u8 type, u8 code, int offset, __be32 info) 647 { 648 struct net *net = dev_net(skb->dev); 649 struct ipv6hdr *iph = (struct ipv6hdr *)skb->data; 650 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset); 651 struct xfrm_state *x; 652 653 if (type != ICMPV6_PKT_TOOBIG && 654 type != NDISC_REDIRECT) 655 return 0; 656 657 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); 658 if (!x) 659 return 0; 660 661 if (type == NDISC_REDIRECT) 662 ip6_redirect(skb, net, skb->dev->ifindex, 0, 663 sock_net_uid(net, NULL)); 664 else 665 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 666 xfrm_state_put(x); 667 668 return 0; 669 } 670 671 static int ah6_init_state(struct xfrm_state *x) 672 { 673 struct ah_data *ahp = NULL; 674 struct xfrm_algo_desc *aalg_desc; 675 struct crypto_ahash *ahash; 676 677 if (!x->aalg) 678 goto error; 679 680 if (x->encap) 681 goto error; 682 683 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); 684 if (!ahp) 685 return -ENOMEM; 686 687 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); 688 if (IS_ERR(ahash)) 689 goto error; 690 691 ahp->ahash = ahash; 692 if (crypto_ahash_setkey(ahash, x->aalg->alg_key, 693 (x->aalg->alg_key_len + 7) / 8)) 694 goto error; 695 696 /* 697 * Lookup the algorithm description maintained by xfrm_algo, 698 * verify crypto transform properties, and store information 699 * we need for AH processing. This lookup cannot fail here 700 * after a successful crypto_alloc_hash(). 701 */ 702 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 703 BUG_ON(!aalg_desc); 704 705 if (aalg_desc->uinfo.auth.icv_fullbits/8 != 706 crypto_ahash_digestsize(ahash)) { 707 pr_info("AH: %s digestsize %u != %hu\n", 708 x->aalg->alg_name, crypto_ahash_digestsize(ahash), 709 aalg_desc->uinfo.auth.icv_fullbits/8); 710 goto error; 711 } 712 713 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; 714 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; 715 716 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + 717 ahp->icv_trunc_len); 718 switch (x->props.mode) { 719 case XFRM_MODE_BEET: 720 case XFRM_MODE_TRANSPORT: 721 break; 722 case XFRM_MODE_TUNNEL: 723 x->props.header_len += sizeof(struct ipv6hdr); 724 break; 725 default: 726 goto error; 727 } 728 x->data = ahp; 729 730 return 0; 731 732 error: 733 if (ahp) { 734 crypto_free_ahash(ahp->ahash); 735 kfree(ahp); 736 } 737 return -EINVAL; 738 } 739 740 static void ah6_destroy(struct xfrm_state *x) 741 { 742 struct ah_data *ahp = x->data; 743 744 if (!ahp) 745 return; 746 747 crypto_free_ahash(ahp->ahash); 748 kfree(ahp); 749 } 750 751 static int ah6_rcv_cb(struct sk_buff *skb, int err) 752 { 753 return 0; 754 } 755 756 static const struct xfrm_type ah6_type = { 757 .description = "AH6", 758 .owner = THIS_MODULE, 759 .proto = IPPROTO_AH, 760 .flags = XFRM_TYPE_REPLAY_PROT, 761 .init_state = ah6_init_state, 762 .destructor = ah6_destroy, 763 .input = ah6_input, 764 .output = ah6_output, 765 .hdr_offset = xfrm6_find_1stfragopt, 766 }; 767 768 static struct xfrm6_protocol ah6_protocol = { 769 .handler = xfrm6_rcv, 770 .cb_handler = ah6_rcv_cb, 771 .err_handler = ah6_err, 772 .priority = 0, 773 }; 774 775 static int __init ah6_init(void) 776 { 777 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) { 778 pr_info("%s: can't add xfrm type\n", __func__); 779 return -EAGAIN; 780 } 781 782 if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) { 783 pr_info("%s: can't add protocol\n", __func__); 784 xfrm_unregister_type(&ah6_type, AF_INET6); 785 return -EAGAIN; 786 } 787 788 return 0; 789 } 790 791 static void __exit ah6_fini(void) 792 { 793 if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0) 794 pr_info("%s: can't remove protocol\n", __func__); 795 796 xfrm_unregister_type(&ah6_type, AF_INET6); 797 } 798 799 module_init(ah6_init); 800 module_exit(ah6_fini); 801 802 MODULE_LICENSE("GPL"); 803 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH); 804