1/* 2 * Copyright (C)2002 USAGI/WIDE Project 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see <http://www.gnu.org/licenses/>. 16 * 17 * Authors 18 * 19 * Mitsuru KANDA @USAGI : IPv6 Support 20 * Kazunori MIYAZAWA @USAGI : 21 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 22 * 23 * This file is derived from net/ipv4/ah.c. 24 */ 25 26#define pr_fmt(fmt) "IPv6: " fmt 27 28#include <crypto/hash.h> 29#include <linux/module.h> 30#include <linux/slab.h> 31#include <net/ip.h> 32#include <net/ah.h> 33#include <linux/crypto.h> 34#include <linux/pfkeyv2.h> 35#include <linux/string.h> 36#include <linux/scatterlist.h> 37#include <net/ip6_route.h> 38#include <net/icmp.h> 39#include <net/ipv6.h> 40#include <net/protocol.h> 41#include <net/xfrm.h> 42 43#define IPV6HDR_BASELEN 8 44 45struct tmp_ext { 46#if IS_ENABLED(CONFIG_IPV6_MIP6) 47 struct in6_addr saddr; 48#endif 49 struct in6_addr daddr; 50 char hdrs[0]; 51}; 52 53struct ah_skb_cb { 54 struct xfrm_skb_cb xfrm; 55 void *tmp; 56}; 57 58#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0])) 59 60static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags, 61 unsigned int size) 62{ 63 unsigned int len; 64 65 len = size + crypto_ahash_digestsize(ahash) + 66 (crypto_ahash_alignmask(ahash) & 67 ~(crypto_tfm_ctx_alignment() - 1)); 68 69 len = ALIGN(len, crypto_tfm_ctx_alignment()); 70 71 len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); 72 len = ALIGN(len, __alignof__(struct scatterlist)); 73 74 len += sizeof(struct scatterlist) * nfrags; 75 76 return kmalloc(len, GFP_ATOMIC); 77} 78 79static inline struct tmp_ext *ah_tmp_ext(void *base) 80{ 81 return base + IPV6HDR_BASELEN; 82} 83 84static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset) 85{ 86 return tmp + offset; 87} 88 89static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp, 90 unsigned int offset) 91{ 92 return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1); 93} 94 95static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, 96 u8 *icv) 97{ 98 struct ahash_request *req; 99 100 req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), 101 crypto_tfm_ctx_alignment()); 102 103 ahash_request_set_tfm(req, ahash); 104 105 return req; 106} 107 108static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, 109 struct ahash_request *req) 110{ 111 return (void *)ALIGN((unsigned long)(req + 1) + 112 crypto_ahash_reqsize(ahash), 113 __alignof__(struct scatterlist)); 114} 115 116static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr) 117{ 118 u8 *opt = (u8 *)opthdr; 119 int len = ipv6_optlen(opthdr); 120 int off = 0; 121 int optlen = 0; 122 123 off += 2; 124 len -= 2; 125 126 while (len > 0) { 127 128 switch (opt[off]) { 129 130 case IPV6_TLV_PAD1: 131 optlen = 1; 132 break; 133 default: 134 if (len < 2) 135 goto bad; 136 optlen = opt[off+1]+2; 137 if (len < optlen) 138 goto bad; 139 if (opt[off] & 0x20) 140 memset(&opt[off+2], 0, opt[off+1]); 141 break; 142 } 143 144 off += optlen; 145 len -= optlen; 146 } 147 if (len == 0) 148 return true; 149 150bad: 151 return false; 152} 153 154#if IS_ENABLED(CONFIG_IPV6_MIP6) 155/** 156 * ipv6_rearrange_destopt - rearrange IPv6 destination options header 157 * @iph: IPv6 header 158 * @destopt: destionation options header 159 */ 160static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) 161{ 162 u8 *opt = (u8 *)destopt; 163 int len = ipv6_optlen(destopt); 164 int off = 0; 165 int optlen = 0; 166 167 off += 2; 168 len -= 2; 169 170 while (len > 0) { 171 172 switch (opt[off]) { 173 174 case IPV6_TLV_PAD1: 175 optlen = 1; 176 break; 177 default: 178 if (len < 2) 179 goto bad; 180 optlen = opt[off+1]+2; 181 if (len < optlen) 182 goto bad; 183 184 /* Rearrange the source address in @iph and the 185 * addresses in home address option for final source. 186 * See 11.3.2 of RFC 3775 for details. 187 */ 188 if (opt[off] == IPV6_TLV_HAO) { 189 struct in6_addr final_addr; 190 struct ipv6_destopt_hao *hao; 191 192 hao = (struct ipv6_destopt_hao *)&opt[off]; 193 if (hao->length != sizeof(hao->addr)) { 194 net_warn_ratelimited("destopt hao: invalid header length: %u\n", 195 hao->length); 196 goto bad; 197 } 198 final_addr = hao->addr; 199 hao->addr = iph->saddr; 200 iph->saddr = final_addr; 201 } 202 break; 203 } 204 205 off += optlen; 206 len -= optlen; 207 } 208 /* Note: ok if len == 0 */ 209bad: 210 return; 211} 212#else 213static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} 214#endif 215 216/** 217 * ipv6_rearrange_rthdr - rearrange IPv6 routing header 218 * @iph: IPv6 header 219 * @rthdr: routing header 220 * 221 * Rearrange the destination address in @iph and the addresses in @rthdr 222 * so that they appear in the order they will at the final destination. 223 * See Appendix A2 of RFC 2402 for details. 224 */ 225static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) 226{ 227 int segments, segments_left; 228 struct in6_addr *addrs; 229 struct in6_addr final_addr; 230 231 segments_left = rthdr->segments_left; 232 if (segments_left == 0) 233 return; 234 rthdr->segments_left = 0; 235 236 /* The value of rthdr->hdrlen has been verified either by the system 237 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming 238 * packets. So we can assume that it is even and that segments is 239 * greater than or equal to segments_left. 240 * 241 * For the same reason we can assume that this option is of type 0. 242 */ 243 segments = rthdr->hdrlen >> 1; 244 245 addrs = ((struct rt0_hdr *)rthdr)->addr; 246 final_addr = addrs[segments - 1]; 247 248 addrs += segments - segments_left; 249 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); 250 251 addrs[0] = iph->daddr; 252 iph->daddr = final_addr; 253} 254 255static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) 256{ 257 union { 258 struct ipv6hdr *iph; 259 struct ipv6_opt_hdr *opth; 260 struct ipv6_rt_hdr *rth; 261 char *raw; 262 } exthdr = { .iph = iph }; 263 char *end = exthdr.raw + len; 264 int nexthdr = iph->nexthdr; 265 266 exthdr.iph++; 267 268 while (exthdr.raw < end) { 269 switch (nexthdr) { 270 case NEXTHDR_DEST: 271 if (dir == XFRM_POLICY_OUT) 272 ipv6_rearrange_destopt(iph, exthdr.opth); 273 case NEXTHDR_HOP: 274 if (!zero_out_mutable_opts(exthdr.opth)) { 275 LIMIT_NETDEBUG( 276 KERN_WARNING "overrun %sopts\n", 277 nexthdr == NEXTHDR_HOP ? 278 "hop" : "dest"); 279 return -EINVAL; 280 } 281 break; 282 283 case NEXTHDR_ROUTING: 284 ipv6_rearrange_rthdr(iph, exthdr.rth); 285 break; 286 287 default: 288 return 0; 289 } 290 291 nexthdr = exthdr.opth->nexthdr; 292 exthdr.raw += ipv6_optlen(exthdr.opth); 293 } 294 295 return 0; 296} 297 298static void ah6_output_done(struct crypto_async_request *base, int err) 299{ 300 int extlen; 301 u8 *iph_base; 302 u8 *icv; 303 struct sk_buff *skb = base->data; 304 struct xfrm_state *x = skb_dst(skb)->xfrm; 305 struct ah_data *ahp = x->data; 306 struct ipv6hdr *top_iph = ipv6_hdr(skb); 307 struct ip_auth_hdr *ah = ip_auth_hdr(skb); 308 struct tmp_ext *iph_ext; 309 310 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); 311 if (extlen) 312 extlen += sizeof(*iph_ext); 313 314 iph_base = AH_SKB_CB(skb)->tmp; 315 iph_ext = ah_tmp_ext(iph_base); 316 icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); 317 318 memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 319 memcpy(top_iph, iph_base, IPV6HDR_BASELEN); 320 321 if (extlen) { 322#if IS_ENABLED(CONFIG_IPV6_MIP6) 323 memcpy(&top_iph->saddr, iph_ext, extlen); 324#else 325 memcpy(&top_iph->daddr, iph_ext, extlen); 326#endif 327 } 328 329 kfree(AH_SKB_CB(skb)->tmp); 330 xfrm_output_resume(skb, err); 331} 332 333static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) 334{ 335 int err; 336 int nfrags; 337 int extlen; 338 u8 *iph_base; 339 u8 *icv; 340 u8 nexthdr; 341 struct sk_buff *trailer; 342 struct crypto_ahash *ahash; 343 struct ahash_request *req; 344 struct scatterlist *sg; 345 struct ipv6hdr *top_iph; 346 struct ip_auth_hdr *ah; 347 struct ah_data *ahp; 348 struct tmp_ext *iph_ext; 349 int seqhi_len = 0; 350 __be32 *seqhi; 351 int sglists = 0; 352 struct scatterlist *seqhisg; 353 354 ahp = x->data; 355 ahash = ahp->ahash; 356 357 if ((err = skb_cow_data(skb, 0, &trailer)) < 0) 358 goto out; 359 nfrags = err; 360 361 skb_push(skb, -skb_network_offset(skb)); 362 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); 363 if (extlen) 364 extlen += sizeof(*iph_ext); 365 366 if (x->props.flags & XFRM_STATE_ESN) { 367 sglists = 1; 368 seqhi_len = sizeof(*seqhi); 369 } 370 err = -ENOMEM; 371 iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN + 372 extlen + seqhi_len); 373 if (!iph_base) 374 goto out; 375 376 iph_ext = ah_tmp_ext(iph_base); 377 seqhi = (__be32 *)((char *)iph_ext + extlen); 378 icv = ah_tmp_icv(ahash, seqhi, seqhi_len); 379 req = ah_tmp_req(ahash, icv); 380 sg = ah_req_sg(ahash, req); 381 seqhisg = sg + nfrags; 382 383 ah = ip_auth_hdr(skb); 384 memset(ah->auth_data, 0, ahp->icv_trunc_len); 385 386 top_iph = ipv6_hdr(skb); 387 top_iph->payload_len = htons(skb->len - sizeof(*top_iph)); 388 389 nexthdr = *skb_mac_header(skb); 390 *skb_mac_header(skb) = IPPROTO_AH; 391 392 /* When there are no extension headers, we only need to save the first 393 * 8 bytes of the base IP header. 394 */ 395 memcpy(iph_base, top_iph, IPV6HDR_BASELEN); 396 397 if (extlen) { 398#if IS_ENABLED(CONFIG_IPV6_MIP6) 399 memcpy(iph_ext, &top_iph->saddr, extlen); 400#else 401 memcpy(iph_ext, &top_iph->daddr, extlen); 402#endif 403 err = ipv6_clear_mutable_options(top_iph, 404 extlen - sizeof(*iph_ext) + 405 sizeof(*top_iph), 406 XFRM_POLICY_OUT); 407 if (err) 408 goto out_free; 409 } 410 411 ah->nexthdr = nexthdr; 412 413 top_iph->priority = 0; 414 top_iph->flow_lbl[0] = 0; 415 top_iph->flow_lbl[1] = 0; 416 top_iph->flow_lbl[2] = 0; 417 top_iph->hop_limit = 0; 418 419 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; 420 421 ah->reserved = 0; 422 ah->spi = x->id.spi; 423 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 424 425 sg_init_table(sg, nfrags + sglists); 426 skb_to_sgvec_nomark(skb, sg, 0, skb->len); 427 428 if (x->props.flags & XFRM_STATE_ESN) { 429 /* Attach seqhi sg right after packet payload */ 430 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); 431 sg_set_buf(seqhisg, seqhi, seqhi_len); 432 } 433 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); 434 ahash_request_set_callback(req, 0, ah6_output_done, skb); 435 436 AH_SKB_CB(skb)->tmp = iph_base; 437 438 err = crypto_ahash_digest(req); 439 if (err) { 440 if (err == -EINPROGRESS) 441 goto out; 442 443 if (err == -EBUSY) 444 err = NET_XMIT_DROP; 445 goto out_free; 446 } 447 448 memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 449 memcpy(top_iph, iph_base, IPV6HDR_BASELEN); 450 451 if (extlen) { 452#if IS_ENABLED(CONFIG_IPV6_MIP6) 453 memcpy(&top_iph->saddr, iph_ext, extlen); 454#else 455 memcpy(&top_iph->daddr, iph_ext, extlen); 456#endif 457 } 458 459out_free: 460 kfree(iph_base); 461out: 462 return err; 463} 464 465static void ah6_input_done(struct crypto_async_request *base, int err) 466{ 467 u8 *auth_data; 468 u8 *icv; 469 u8 *work_iph; 470 struct sk_buff *skb = base->data; 471 struct xfrm_state *x = xfrm_input_state(skb); 472 struct ah_data *ahp = x->data; 473 struct ip_auth_hdr *ah = ip_auth_hdr(skb); 474 int hdr_len = skb_network_header_len(skb); 475 int ah_hlen = (ah->hdrlen + 2) << 2; 476 477 work_iph = AH_SKB_CB(skb)->tmp; 478 auth_data = ah_tmp_auth(work_iph, hdr_len); 479 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); 480 481 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; 482 if (err) 483 goto out; 484 485 err = ah->nexthdr; 486 487 skb->network_header += ah_hlen; 488 memcpy(skb_network_header(skb), work_iph, hdr_len); 489 __skb_pull(skb, ah_hlen + hdr_len); 490 if (x->props.mode == XFRM_MODE_TUNNEL) 491 skb_reset_transport_header(skb); 492 else 493 skb_set_transport_header(skb, -hdr_len); 494out: 495 kfree(AH_SKB_CB(skb)->tmp); 496 xfrm_input_resume(skb, err); 497} 498 499 500 501static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) 502{ 503 /* 504 * Before process AH 505 * [IPv6][Ext1][Ext2][AH][Dest][Payload] 506 * |<-------------->| hdr_len 507 * 508 * To erase AH: 509 * Keeping copy of cleared headers. After AH processing, 510 * Moving the pointer of skb->network_header by using skb_pull as long 511 * as AH header length. Then copy back the copy as long as hdr_len 512 * If destination header following AH exists, copy it into after [Ext2]. 513 * 514 * |<>|[IPv6][Ext1][Ext2][Dest][Payload] 515 * There is offset of AH before IPv6 header after the process. 516 */ 517 518 u8 *auth_data; 519 u8 *icv; 520 u8 *work_iph; 521 struct sk_buff *trailer; 522 struct crypto_ahash *ahash; 523 struct ahash_request *req; 524 struct scatterlist *sg; 525 struct ip_auth_hdr *ah; 526 struct ipv6hdr *ip6h; 527 struct ah_data *ahp; 528 u16 hdr_len; 529 u16 ah_hlen; 530 int nexthdr; 531 int nfrags; 532 int err = -ENOMEM; 533 int seqhi_len = 0; 534 __be32 *seqhi; 535 int sglists = 0; 536 struct scatterlist *seqhisg; 537 538 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) 539 goto out; 540 541 /* We are going to _remove_ AH header to keep sockets happy, 542 * so... Later this can change. */ 543 if (skb_unclone(skb, GFP_ATOMIC)) 544 goto out; 545 546 skb->ip_summed = CHECKSUM_NONE; 547 548 hdr_len = skb_network_header_len(skb); 549 ah = (struct ip_auth_hdr *)skb->data; 550 ahp = x->data; 551 ahash = ahp->ahash; 552 553 nexthdr = ah->nexthdr; 554 ah_hlen = (ah->hdrlen + 2) << 2; 555 556 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && 557 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) 558 goto out; 559 560 if (!pskb_may_pull(skb, ah_hlen)) 561 goto out; 562 563 564 if ((err = skb_cow_data(skb, 0, &trailer)) < 0) 565 goto out; 566 nfrags = err; 567 568 ah = (struct ip_auth_hdr *)skb->data; 569 ip6h = ipv6_hdr(skb); 570 571 skb_push(skb, hdr_len); 572 573 if (x->props.flags & XFRM_STATE_ESN) { 574 sglists = 1; 575 seqhi_len = sizeof(*seqhi); 576 } 577 578 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len + 579 ahp->icv_trunc_len + seqhi_len); 580 if (!work_iph) 581 goto out; 582 583 auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len); 584 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len); 585 icv = ah_tmp_icv(ahash, seqhi, seqhi_len); 586 req = ah_tmp_req(ahash, icv); 587 sg = ah_req_sg(ahash, req); 588 seqhisg = sg + nfrags; 589 590 memcpy(work_iph, ip6h, hdr_len); 591 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); 592 memset(ah->auth_data, 0, ahp->icv_trunc_len); 593 594 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN)) 595 goto out_free; 596 597 ip6h->priority = 0; 598 ip6h->flow_lbl[0] = 0; 599 ip6h->flow_lbl[1] = 0; 600 ip6h->flow_lbl[2] = 0; 601 ip6h->hop_limit = 0; 602 603 sg_init_table(sg, nfrags + sglists); 604 skb_to_sgvec_nomark(skb, sg, 0, skb->len); 605 606 if (x->props.flags & XFRM_STATE_ESN) { 607 /* Attach seqhi sg right after packet payload */ 608 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; 609 sg_set_buf(seqhisg, seqhi, seqhi_len); 610 } 611 612 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); 613 ahash_request_set_callback(req, 0, ah6_input_done, skb); 614 615 AH_SKB_CB(skb)->tmp = work_iph; 616 617 err = crypto_ahash_digest(req); 618 if (err) { 619 if (err == -EINPROGRESS) 620 goto out; 621 622 goto out_free; 623 } 624 625 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; 626 if (err) 627 goto out_free; 628 629 skb->network_header += ah_hlen; 630 memcpy(skb_network_header(skb), work_iph, hdr_len); 631 __skb_pull(skb, ah_hlen + hdr_len); 632 633 if (x->props.mode == XFRM_MODE_TUNNEL) 634 skb_reset_transport_header(skb); 635 else 636 skb_set_transport_header(skb, -hdr_len); 637 638 err = nexthdr; 639 640out_free: 641 kfree(work_iph); 642out: 643 return err; 644} 645 646static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 647 u8 type, u8 code, int offset, __be32 info) 648{ 649 struct net *net = dev_net(skb->dev); 650 struct ipv6hdr *iph = (struct ipv6hdr *)skb->data; 651 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset); 652 struct xfrm_state *x; 653 654 if (type != ICMPV6_PKT_TOOBIG && 655 type != NDISC_REDIRECT) 656 return 0; 657 658 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); 659 if (!x) 660 return 0; 661 662 if (type == NDISC_REDIRECT) 663 ip6_redirect(skb, net, skb->dev->ifindex, 0); 664 else 665 ip6_update_pmtu(skb, net, info, 0, 0, INVALID_UID); 666 xfrm_state_put(x); 667 668 return 0; 669} 670 671static 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 == NULL) 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 732error: 733 if (ahp) { 734 crypto_free_ahash(ahp->ahash); 735 kfree(ahp); 736 } 737 return -EINVAL; 738} 739 740static 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 751static int ah6_rcv_cb(struct sk_buff *skb, int err) 752{ 753 return 0; 754} 755 756static 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 768static 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 775static 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 791static 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 if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0) 797 pr_info("%s: can't remove xfrm type\n", __func__); 798 799} 800 801module_init(ah6_init); 802module_exit(ah6_fini); 803 804MODULE_LICENSE("GPL"); 805MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH); 806