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 45 struct 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 53 struct 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 60 static 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 79 static inline struct tmp_ext *ah_tmp_ext(void *base) 80 { 81 return base + IPV6HDR_BASELEN; 82 } 83 84 static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset) 85 { 86 return tmp + offset; 87 } 88 89 static 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 95 static 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 } 107 108 static 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 } 115 116 static 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; 149 150 bad: 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 */ 160 static 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 */ 209 bad: 210 return; 211 } 212 #else 213 static 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 */ 225 static 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 } 254 255 static 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 net_dbg_ratelimited("overrun %sopts\n", 276 nexthdr == NEXTHDR_HOP ? 277 "hop" : "dest"); 278 return -EINVAL; 279 } 280 break; 281 282 case NEXTHDR_ROUTING: 283 ipv6_rearrange_rthdr(iph, exthdr.rth); 284 break; 285 286 default: 287 return 0; 288 } 289 290 nexthdr = exthdr.opth->nexthdr; 291 exthdr.raw += ipv6_optlen(exthdr.opth); 292 } 293 294 return 0; 295 } 296 297 static void ah6_output_done(struct crypto_async_request *base, int err) 298 { 299 int extlen; 300 u8 *iph_base; 301 u8 *icv; 302 struct sk_buff *skb = base->data; 303 struct xfrm_state *x = skb_dst(skb)->xfrm; 304 struct ah_data *ahp = x->data; 305 struct ipv6hdr *top_iph = ipv6_hdr(skb); 306 struct ip_auth_hdr *ah = ip_auth_hdr(skb); 307 struct tmp_ext *iph_ext; 308 309 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); 310 if (extlen) 311 extlen += sizeof(*iph_ext); 312 313 iph_base = AH_SKB_CB(skb)->tmp; 314 iph_ext = ah_tmp_ext(iph_base); 315 icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); 316 317 memcpy(ah->auth_data, icv, ahp->icv_trunc_len); 318 memcpy(top_iph, iph_base, IPV6HDR_BASELEN); 319 320 if (extlen) { 321 #if IS_ENABLED(CONFIG_IPV6_MIP6) 322 memcpy(&top_iph->saddr, iph_ext, extlen); 323 #else 324 memcpy(&top_iph->daddr, iph_ext, extlen); 325 #endif 326 } 327 328 kfree(AH_SKB_CB(skb)->tmp); 329 xfrm_output_resume(skb, err); 330 } 331 332 static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) 333 { 334 int err; 335 int nfrags; 336 int extlen; 337 u8 *iph_base; 338 u8 *icv; 339 u8 nexthdr; 340 struct sk_buff *trailer; 341 struct crypto_ahash *ahash; 342 struct ahash_request *req; 343 struct scatterlist *sg; 344 struct ipv6hdr *top_iph; 345 struct ip_auth_hdr *ah; 346 struct ah_data *ahp; 347 struct tmp_ext *iph_ext; 348 int seqhi_len = 0; 349 __be32 *seqhi; 350 int sglists = 0; 351 struct scatterlist *seqhisg; 352 353 ahp = x->data; 354 ahash = ahp->ahash; 355 356 err = skb_cow_data(skb, 0, &trailer); 357 if (err < 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 } 458 459 out_free: 460 kfree(iph_base); 461 out: 462 return err; 463 } 464 465 static 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 if (err) 478 goto out; 479 480 work_iph = AH_SKB_CB(skb)->tmp; 481 auth_data = ah_tmp_auth(work_iph, hdr_len); 482 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); 483 484 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; 485 if (err) 486 goto out; 487 488 err = ah->nexthdr; 489 490 skb->network_header += ah_hlen; 491 memcpy(skb_network_header(skb), work_iph, hdr_len); 492 __skb_pull(skb, ah_hlen + hdr_len); 493 if (x->props.mode == XFRM_MODE_TUNNEL) 494 skb_reset_transport_header(skb); 495 else 496 skb_set_transport_header(skb, -hdr_len); 497 out: 498 kfree(AH_SKB_CB(skb)->tmp); 499 xfrm_input_resume(skb, err); 500 } 501 502 503 504 static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) 505 { 506 /* 507 * Before process AH 508 * [IPv6][Ext1][Ext2][AH][Dest][Payload] 509 * |<-------------->| hdr_len 510 * 511 * To erase AH: 512 * Keeping copy of cleared headers. After AH processing, 513 * Moving the pointer of skb->network_header by using skb_pull as long 514 * as AH header length. Then copy back the copy as long as hdr_len 515 * If destination header following AH exists, copy it into after [Ext2]. 516 * 517 * |<>|[IPv6][Ext1][Ext2][Dest][Payload] 518 * There is offset of AH before IPv6 header after the process. 519 */ 520 521 u8 *auth_data; 522 u8 *icv; 523 u8 *work_iph; 524 struct sk_buff *trailer; 525 struct crypto_ahash *ahash; 526 struct ahash_request *req; 527 struct scatterlist *sg; 528 struct ip_auth_hdr *ah; 529 struct ipv6hdr *ip6h; 530 struct ah_data *ahp; 531 u16 hdr_len; 532 u16 ah_hlen; 533 int nexthdr; 534 int nfrags; 535 int err = -ENOMEM; 536 int seqhi_len = 0; 537 __be32 *seqhi; 538 int sglists = 0; 539 struct scatterlist *seqhisg; 540 541 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) 542 goto out; 543 544 /* We are going to _remove_ AH header to keep sockets happy, 545 * so... Later this can change. */ 546 if (skb_unclone(skb, GFP_ATOMIC)) 547 goto out; 548 549 skb->ip_summed = CHECKSUM_NONE; 550 551 hdr_len = skb_network_header_len(skb); 552 ah = (struct ip_auth_hdr *)skb->data; 553 ahp = x->data; 554 ahash = ahp->ahash; 555 556 nexthdr = ah->nexthdr; 557 ah_hlen = (ah->hdrlen + 2) << 2; 558 559 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && 560 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) 561 goto out; 562 563 if (!pskb_may_pull(skb, ah_hlen)) 564 goto out; 565 566 err = skb_cow_data(skb, 0, &trailer); 567 if (err < 0) 568 goto out; 569 nfrags = err; 570 571 ah = (struct ip_auth_hdr *)skb->data; 572 ip6h = ipv6_hdr(skb); 573 574 skb_push(skb, hdr_len); 575 576 if (x->props.flags & XFRM_STATE_ESN) { 577 sglists = 1; 578 seqhi_len = sizeof(*seqhi); 579 } 580 581 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len + 582 ahp->icv_trunc_len + seqhi_len); 583 if (!work_iph) { 584 err = -ENOMEM; 585 goto out; 586 } 587 588 auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len); 589 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len); 590 icv = ah_tmp_icv(ahash, seqhi, seqhi_len); 591 req = ah_tmp_req(ahash, icv); 592 sg = ah_req_sg(ahash, req); 593 seqhisg = sg + nfrags; 594 595 memcpy(work_iph, ip6h, hdr_len); 596 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); 597 memset(ah->auth_data, 0, ahp->icv_trunc_len); 598 599 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN)) 600 goto out_free; 601 602 ip6h->priority = 0; 603 ip6h->flow_lbl[0] = 0; 604 ip6h->flow_lbl[1] = 0; 605 ip6h->flow_lbl[2] = 0; 606 ip6h->hop_limit = 0; 607 608 sg_init_table(sg, nfrags + sglists); 609 skb_to_sgvec_nomark(skb, sg, 0, skb->len); 610 611 if (x->props.flags & XFRM_STATE_ESN) { 612 /* Attach seqhi sg right after packet payload */ 613 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; 614 sg_set_buf(seqhisg, seqhi, seqhi_len); 615 } 616 617 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); 618 ahash_request_set_callback(req, 0, ah6_input_done, skb); 619 620 AH_SKB_CB(skb)->tmp = work_iph; 621 622 err = crypto_ahash_digest(req); 623 if (err) { 624 if (err == -EINPROGRESS) 625 goto out; 626 627 goto out_free; 628 } 629 630 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; 631 if (err) 632 goto out_free; 633 634 skb->network_header += ah_hlen; 635 memcpy(skb_network_header(skb), work_iph, hdr_len); 636 __skb_pull(skb, ah_hlen + hdr_len); 637 638 if (x->props.mode == XFRM_MODE_TUNNEL) 639 skb_reset_transport_header(skb); 640 else 641 skb_set_transport_header(skb, -hdr_len); 642 643 err = nexthdr; 644 645 out_free: 646 kfree(work_iph); 647 out: 648 return err; 649 } 650 651 static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 652 u8 type, u8 code, int offset, __be32 info) 653 { 654 struct net *net = dev_net(skb->dev); 655 struct ipv6hdr *iph = (struct ipv6hdr *)skb->data; 656 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset); 657 struct xfrm_state *x; 658 659 if (type != ICMPV6_PKT_TOOBIG && 660 type != NDISC_REDIRECT) 661 return 0; 662 663 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); 664 if (!x) 665 return 0; 666 667 if (type == NDISC_REDIRECT) 668 ip6_redirect(skb, net, skb->dev->ifindex, 0, 669 sock_net_uid(net, NULL)); 670 else 671 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 672 xfrm_state_put(x); 673 674 return 0; 675 } 676 677 static int ah6_init_state(struct xfrm_state *x) 678 { 679 struct ah_data *ahp = NULL; 680 struct xfrm_algo_desc *aalg_desc; 681 struct crypto_ahash *ahash; 682 683 if (!x->aalg) 684 goto error; 685 686 if (x->encap) 687 goto error; 688 689 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); 690 if (!ahp) 691 return -ENOMEM; 692 693 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); 694 if (IS_ERR(ahash)) 695 goto error; 696 697 ahp->ahash = ahash; 698 if (crypto_ahash_setkey(ahash, x->aalg->alg_key, 699 (x->aalg->alg_key_len + 7) / 8)) 700 goto error; 701 702 /* 703 * Lookup the algorithm description maintained by xfrm_algo, 704 * verify crypto transform properties, and store information 705 * we need for AH processing. This lookup cannot fail here 706 * after a successful crypto_alloc_hash(). 707 */ 708 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 709 BUG_ON(!aalg_desc); 710 711 if (aalg_desc->uinfo.auth.icv_fullbits/8 != 712 crypto_ahash_digestsize(ahash)) { 713 pr_info("AH: %s digestsize %u != %hu\n", 714 x->aalg->alg_name, crypto_ahash_digestsize(ahash), 715 aalg_desc->uinfo.auth.icv_fullbits/8); 716 goto error; 717 } 718 719 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; 720 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; 721 722 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + 723 ahp->icv_trunc_len); 724 switch (x->props.mode) { 725 case XFRM_MODE_BEET: 726 case XFRM_MODE_TRANSPORT: 727 break; 728 case XFRM_MODE_TUNNEL: 729 x->props.header_len += sizeof(struct ipv6hdr); 730 break; 731 default: 732 goto error; 733 } 734 x->data = ahp; 735 736 return 0; 737 738 error: 739 if (ahp) { 740 crypto_free_ahash(ahp->ahash); 741 kfree(ahp); 742 } 743 return -EINVAL; 744 } 745 746 static void ah6_destroy(struct xfrm_state *x) 747 { 748 struct ah_data *ahp = x->data; 749 750 if (!ahp) 751 return; 752 753 crypto_free_ahash(ahp->ahash); 754 kfree(ahp); 755 } 756 757 static int ah6_rcv_cb(struct sk_buff *skb, int err) 758 { 759 return 0; 760 } 761 762 static const struct xfrm_type ah6_type = { 763 .description = "AH6", 764 .owner = THIS_MODULE, 765 .proto = IPPROTO_AH, 766 .flags = XFRM_TYPE_REPLAY_PROT, 767 .init_state = ah6_init_state, 768 .destructor = ah6_destroy, 769 .input = ah6_input, 770 .output = ah6_output, 771 .hdr_offset = xfrm6_find_1stfragopt, 772 }; 773 774 static struct xfrm6_protocol ah6_protocol = { 775 .handler = xfrm6_rcv, 776 .cb_handler = ah6_rcv_cb, 777 .err_handler = ah6_err, 778 .priority = 0, 779 }; 780 781 static int __init ah6_init(void) 782 { 783 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) { 784 pr_info("%s: can't add xfrm type\n", __func__); 785 return -EAGAIN; 786 } 787 788 if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) { 789 pr_info("%s: can't add protocol\n", __func__); 790 xfrm_unregister_type(&ah6_type, AF_INET6); 791 return -EAGAIN; 792 } 793 794 return 0; 795 } 796 797 static void __exit ah6_fini(void) 798 { 799 if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0) 800 pr_info("%s: can't remove protocol\n", __func__); 801 802 if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0) 803 pr_info("%s: can't remove xfrm type\n", __func__); 804 805 } 806 807 module_init(ah6_init); 808 module_exit(ah6_fini); 809 810 MODULE_LICENSE("GPL"); 811 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH); 812