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/esp.c 24 */ 25 26 #define pr_fmt(fmt) "IPv6: " fmt 27 28 #include <crypto/aead.h> 29 #include <crypto/authenc.h> 30 #include <linux/err.h> 31 #include <linux/module.h> 32 #include <net/ip.h> 33 #include <net/xfrm.h> 34 #include <net/esp.h> 35 #include <linux/scatterlist.h> 36 #include <linux/kernel.h> 37 #include <linux/pfkeyv2.h> 38 #include <linux/random.h> 39 #include <linux/slab.h> 40 #include <linux/spinlock.h> 41 #include <net/ip6_route.h> 42 #include <net/icmp.h> 43 #include <net/ipv6.h> 44 #include <net/protocol.h> 45 #include <linux/icmpv6.h> 46 47 #include <linux/highmem.h> 48 49 struct esp_skb_cb { 50 struct xfrm_skb_cb xfrm; 51 void *tmp; 52 }; 53 54 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) 55 56 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu); 57 58 /* 59 * Allocate an AEAD request structure with extra space for SG and IV. 60 * 61 * For alignment considerations the upper 32 bits of the sequence number are 62 * placed at the front, if present. Followed by the IV, the request and finally 63 * the SG list. 64 * 65 * TODO: Use spare space in skb for this where possible. 66 */ 67 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen) 68 { 69 unsigned int len; 70 71 len = seqihlen; 72 73 len += crypto_aead_ivsize(aead); 74 75 if (len) { 76 len += crypto_aead_alignmask(aead) & 77 ~(crypto_tfm_ctx_alignment() - 1); 78 len = ALIGN(len, crypto_tfm_ctx_alignment()); 79 } 80 81 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); 82 len = ALIGN(len, __alignof__(struct scatterlist)); 83 84 len += sizeof(struct scatterlist) * nfrags; 85 86 return kmalloc(len, GFP_ATOMIC); 87 } 88 89 static inline __be32 *esp_tmp_seqhi(void *tmp) 90 { 91 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32)); 92 } 93 94 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen) 95 { 96 return crypto_aead_ivsize(aead) ? 97 PTR_ALIGN((u8 *)tmp + seqhilen, 98 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen; 99 } 100 101 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) 102 { 103 struct aead_request *req; 104 105 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), 106 crypto_tfm_ctx_alignment()); 107 aead_request_set_tfm(req, aead); 108 return req; 109 } 110 111 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, 112 struct aead_request *req) 113 { 114 return (void *)ALIGN((unsigned long)(req + 1) + 115 crypto_aead_reqsize(aead), 116 __alignof__(struct scatterlist)); 117 } 118 119 static void esp_ssg_unref(struct xfrm_state *x, void *tmp) 120 { 121 struct crypto_aead *aead = x->data; 122 int seqhilen = 0; 123 u8 *iv; 124 struct aead_request *req; 125 struct scatterlist *sg; 126 127 if (x->props.flags & XFRM_STATE_ESN) 128 seqhilen += sizeof(__be32); 129 130 iv = esp_tmp_iv(aead, tmp, seqhilen); 131 req = esp_tmp_req(aead, iv); 132 133 /* Unref skb_frag_pages in the src scatterlist if necessary. 134 * Skip the first sg which comes from skb->data. 135 */ 136 if (req->src != req->dst) 137 for (sg = sg_next(req->src); sg; sg = sg_next(sg)) 138 put_page(sg_page(sg)); 139 } 140 141 static void esp_output_done(struct crypto_async_request *base, int err) 142 { 143 struct sk_buff *skb = base->data; 144 struct xfrm_offload *xo = xfrm_offload(skb); 145 void *tmp; 146 struct xfrm_state *x; 147 148 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 149 struct sec_path *sp = skb_sec_path(skb); 150 151 x = sp->xvec[sp->len - 1]; 152 } else { 153 x = skb_dst(skb)->xfrm; 154 } 155 156 tmp = ESP_SKB_CB(skb)->tmp; 157 esp_ssg_unref(x, tmp); 158 kfree(tmp); 159 160 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 161 if (err) { 162 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 163 kfree_skb(skb); 164 return; 165 } 166 167 skb_push(skb, skb->data - skb_mac_header(skb)); 168 secpath_reset(skb); 169 xfrm_dev_resume(skb); 170 } else { 171 xfrm_output_resume(skb, err); 172 } 173 } 174 175 /* Move ESP header back into place. */ 176 static void esp_restore_header(struct sk_buff *skb, unsigned int offset) 177 { 178 struct ip_esp_hdr *esph = (void *)(skb->data + offset); 179 void *tmp = ESP_SKB_CB(skb)->tmp; 180 __be32 *seqhi = esp_tmp_seqhi(tmp); 181 182 esph->seq_no = esph->spi; 183 esph->spi = *seqhi; 184 } 185 186 static void esp_output_restore_header(struct sk_buff *skb) 187 { 188 esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32)); 189 } 190 191 static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb, 192 struct xfrm_state *x, 193 struct ip_esp_hdr *esph, 194 __be32 *seqhi) 195 { 196 /* For ESN we move the header forward by 4 bytes to 197 * accomodate the high bits. We will move it back after 198 * encryption. 199 */ 200 if ((x->props.flags & XFRM_STATE_ESN)) { 201 struct xfrm_offload *xo = xfrm_offload(skb); 202 203 esph = (void *)(skb_transport_header(skb) - sizeof(__be32)); 204 *seqhi = esph->spi; 205 if (xo) 206 esph->seq_no = htonl(xo->seq.hi); 207 else 208 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi); 209 } 210 211 esph->spi = x->id.spi; 212 213 return esph; 214 } 215 216 static void esp_output_done_esn(struct crypto_async_request *base, int err) 217 { 218 struct sk_buff *skb = base->data; 219 220 esp_output_restore_header(skb); 221 esp_output_done(base, err); 222 } 223 224 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) 225 { 226 /* Fill padding... */ 227 if (tfclen) { 228 memset(tail, 0, tfclen); 229 tail += tfclen; 230 } 231 do { 232 int i; 233 for (i = 0; i < plen - 2; i++) 234 tail[i] = i + 1; 235 } while (0); 236 tail[plen - 2] = plen - 2; 237 tail[plen - 1] = proto; 238 } 239 240 int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 241 { 242 u8 *tail; 243 u8 *vaddr; 244 int nfrags; 245 struct page *page; 246 struct sk_buff *trailer; 247 int tailen = esp->tailen; 248 249 if (!skb_cloned(skb)) { 250 if (tailen <= skb_tailroom(skb)) { 251 nfrags = 1; 252 trailer = skb; 253 tail = skb_tail_pointer(trailer); 254 255 goto skip_cow; 256 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) 257 && !skb_has_frag_list(skb)) { 258 int allocsize; 259 struct sock *sk = skb->sk; 260 struct page_frag *pfrag = &x->xfrag; 261 262 esp->inplace = false; 263 264 allocsize = ALIGN(tailen, L1_CACHE_BYTES); 265 266 spin_lock_bh(&x->lock); 267 268 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 269 spin_unlock_bh(&x->lock); 270 goto cow; 271 } 272 273 page = pfrag->page; 274 get_page(page); 275 276 vaddr = kmap_atomic(page); 277 278 tail = vaddr + pfrag->offset; 279 280 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 281 282 kunmap_atomic(vaddr); 283 284 nfrags = skb_shinfo(skb)->nr_frags; 285 286 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, 287 tailen); 288 skb_shinfo(skb)->nr_frags = ++nfrags; 289 290 pfrag->offset = pfrag->offset + allocsize; 291 292 spin_unlock_bh(&x->lock); 293 294 nfrags++; 295 296 skb->len += tailen; 297 skb->data_len += tailen; 298 skb->truesize += tailen; 299 if (sk && sk_fullsock(sk)) 300 refcount_add(tailen, &sk->sk_wmem_alloc); 301 302 goto out; 303 } 304 } 305 306 cow: 307 nfrags = skb_cow_data(skb, tailen, &trailer); 308 if (nfrags < 0) 309 goto out; 310 tail = skb_tail_pointer(trailer); 311 312 skip_cow: 313 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 314 pskb_put(skb, trailer, tailen); 315 316 out: 317 return nfrags; 318 } 319 EXPORT_SYMBOL_GPL(esp6_output_head); 320 321 int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 322 { 323 u8 *iv; 324 int alen; 325 void *tmp; 326 int ivlen; 327 int assoclen; 328 int seqhilen; 329 __be32 *seqhi; 330 struct page *page; 331 struct ip_esp_hdr *esph; 332 struct aead_request *req; 333 struct crypto_aead *aead; 334 struct scatterlist *sg, *dsg; 335 int err = -ENOMEM; 336 337 assoclen = sizeof(struct ip_esp_hdr); 338 seqhilen = 0; 339 340 if (x->props.flags & XFRM_STATE_ESN) { 341 seqhilen += sizeof(__be32); 342 assoclen += sizeof(__be32); 343 } 344 345 aead = x->data; 346 alen = crypto_aead_authsize(aead); 347 ivlen = crypto_aead_ivsize(aead); 348 349 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen); 350 if (!tmp) 351 goto error; 352 353 seqhi = esp_tmp_seqhi(tmp); 354 iv = esp_tmp_iv(aead, tmp, seqhilen); 355 req = esp_tmp_req(aead, iv); 356 sg = esp_req_sg(aead, req); 357 358 if (esp->inplace) 359 dsg = sg; 360 else 361 dsg = &sg[esp->nfrags]; 362 363 esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi); 364 365 sg_init_table(sg, esp->nfrags); 366 err = skb_to_sgvec(skb, sg, 367 (unsigned char *)esph - skb->data, 368 assoclen + ivlen + esp->clen + alen); 369 if (unlikely(err < 0)) 370 goto error_free; 371 372 if (!esp->inplace) { 373 int allocsize; 374 struct page_frag *pfrag = &x->xfrag; 375 376 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 377 378 spin_lock_bh(&x->lock); 379 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 380 spin_unlock_bh(&x->lock); 381 goto error_free; 382 } 383 384 skb_shinfo(skb)->nr_frags = 1; 385 386 page = pfrag->page; 387 get_page(page); 388 /* replace page frags in skb with new page */ 389 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 390 pfrag->offset = pfrag->offset + allocsize; 391 spin_unlock_bh(&x->lock); 392 393 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 394 err = skb_to_sgvec(skb, dsg, 395 (unsigned char *)esph - skb->data, 396 assoclen + ivlen + esp->clen + alen); 397 if (unlikely(err < 0)) 398 goto error_free; 399 } 400 401 if ((x->props.flags & XFRM_STATE_ESN)) 402 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 403 else 404 aead_request_set_callback(req, 0, esp_output_done, skb); 405 406 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); 407 aead_request_set_ad(req, assoclen); 408 409 memset(iv, 0, ivlen); 410 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), 411 min(ivlen, 8)); 412 413 ESP_SKB_CB(skb)->tmp = tmp; 414 err = crypto_aead_encrypt(req); 415 416 switch (err) { 417 case -EINPROGRESS: 418 goto error; 419 420 case -ENOSPC: 421 err = NET_XMIT_DROP; 422 break; 423 424 case 0: 425 if ((x->props.flags & XFRM_STATE_ESN)) 426 esp_output_restore_header(skb); 427 } 428 429 if (sg != dsg) 430 esp_ssg_unref(x, tmp); 431 432 error_free: 433 kfree(tmp); 434 error: 435 return err; 436 } 437 EXPORT_SYMBOL_GPL(esp6_output_tail); 438 439 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) 440 { 441 int alen; 442 int blksize; 443 struct ip_esp_hdr *esph; 444 struct crypto_aead *aead; 445 struct esp_info esp; 446 447 esp.inplace = true; 448 449 esp.proto = *skb_mac_header(skb); 450 *skb_mac_header(skb) = IPPROTO_ESP; 451 452 /* skb is pure payload to encrypt */ 453 454 aead = x->data; 455 alen = crypto_aead_authsize(aead); 456 457 esp.tfclen = 0; 458 if (x->tfcpad) { 459 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 460 u32 padto; 461 462 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached)); 463 if (skb->len < padto) 464 esp.tfclen = padto - skb->len; 465 } 466 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 467 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); 468 esp.plen = esp.clen - skb->len - esp.tfclen; 469 esp.tailen = esp.tfclen + esp.plen + alen; 470 471 esp.nfrags = esp6_output_head(x, skb, &esp); 472 if (esp.nfrags < 0) 473 return esp.nfrags; 474 475 esph = ip_esp_hdr(skb); 476 esph->spi = x->id.spi; 477 478 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 479 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 480 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 481 482 skb_push(skb, -skb_network_offset(skb)); 483 484 return esp6_output_tail(x, skb, &esp); 485 } 486 487 static inline int esp_remove_trailer(struct sk_buff *skb) 488 { 489 struct xfrm_state *x = xfrm_input_state(skb); 490 struct xfrm_offload *xo = xfrm_offload(skb); 491 struct crypto_aead *aead = x->data; 492 int alen, hlen, elen; 493 int padlen, trimlen; 494 __wsum csumdiff; 495 u8 nexthdr[2]; 496 int ret; 497 498 alen = crypto_aead_authsize(aead); 499 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 500 elen = skb->len - hlen; 501 502 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { 503 ret = xo->proto; 504 goto out; 505 } 506 507 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2); 508 BUG_ON(ret); 509 510 ret = -EINVAL; 511 padlen = nexthdr[0]; 512 if (padlen + 2 + alen >= elen) { 513 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", 514 padlen + 2, elen - alen); 515 goto out; 516 } 517 518 trimlen = alen + padlen + 2; 519 if (skb->ip_summed == CHECKSUM_COMPLETE) { 520 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); 521 skb->csum = csum_block_sub(skb->csum, csumdiff, 522 skb->len - trimlen); 523 } 524 pskb_trim(skb, skb->len - trimlen); 525 526 ret = nexthdr[1]; 527 528 out: 529 return ret; 530 } 531 532 int esp6_input_done2(struct sk_buff *skb, int err) 533 { 534 struct xfrm_state *x = xfrm_input_state(skb); 535 struct xfrm_offload *xo = xfrm_offload(skb); 536 struct crypto_aead *aead = x->data; 537 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 538 int hdr_len = skb_network_header_len(skb); 539 540 if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) 541 kfree(ESP_SKB_CB(skb)->tmp); 542 543 if (unlikely(err)) 544 goto out; 545 546 err = esp_remove_trailer(skb); 547 if (unlikely(err < 0)) 548 goto out; 549 550 skb_postpull_rcsum(skb, skb_network_header(skb), 551 skb_network_header_len(skb)); 552 skb_pull_rcsum(skb, hlen); 553 if (x->props.mode == XFRM_MODE_TUNNEL) 554 skb_reset_transport_header(skb); 555 else 556 skb_set_transport_header(skb, -hdr_len); 557 558 /* RFC4303: Drop dummy packets without any error */ 559 if (err == IPPROTO_NONE) 560 err = -EINVAL; 561 562 out: 563 return err; 564 } 565 EXPORT_SYMBOL_GPL(esp6_input_done2); 566 567 static void esp_input_done(struct crypto_async_request *base, int err) 568 { 569 struct sk_buff *skb = base->data; 570 571 xfrm_input_resume(skb, esp6_input_done2(skb, err)); 572 } 573 574 static void esp_input_restore_header(struct sk_buff *skb) 575 { 576 esp_restore_header(skb, 0); 577 __skb_pull(skb, 4); 578 } 579 580 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 581 { 582 struct xfrm_state *x = xfrm_input_state(skb); 583 584 /* For ESN we move the header forward by 4 bytes to 585 * accomodate the high bits. We will move it back after 586 * decryption. 587 */ 588 if ((x->props.flags & XFRM_STATE_ESN)) { 589 struct ip_esp_hdr *esph = skb_push(skb, 4); 590 591 *seqhi = esph->spi; 592 esph->spi = esph->seq_no; 593 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 594 } 595 } 596 597 static void esp_input_done_esn(struct crypto_async_request *base, int err) 598 { 599 struct sk_buff *skb = base->data; 600 601 esp_input_restore_header(skb); 602 esp_input_done(base, err); 603 } 604 605 static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) 606 { 607 struct crypto_aead *aead = x->data; 608 struct aead_request *req; 609 struct sk_buff *trailer; 610 int ivlen = crypto_aead_ivsize(aead); 611 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen; 612 int nfrags; 613 int assoclen; 614 int seqhilen; 615 int ret = 0; 616 void *tmp; 617 __be32 *seqhi; 618 u8 *iv; 619 struct scatterlist *sg; 620 621 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) { 622 ret = -EINVAL; 623 goto out; 624 } 625 626 if (elen <= 0) { 627 ret = -EINVAL; 628 goto out; 629 } 630 631 assoclen = sizeof(struct ip_esp_hdr); 632 seqhilen = 0; 633 634 if (x->props.flags & XFRM_STATE_ESN) { 635 seqhilen += sizeof(__be32); 636 assoclen += seqhilen; 637 } 638 639 if (!skb_cloned(skb)) { 640 if (!skb_is_nonlinear(skb)) { 641 nfrags = 1; 642 643 goto skip_cow; 644 } else if (!skb_has_frag_list(skb)) { 645 nfrags = skb_shinfo(skb)->nr_frags; 646 nfrags++; 647 648 goto skip_cow; 649 } 650 } 651 652 nfrags = skb_cow_data(skb, 0, &trailer); 653 if (nfrags < 0) { 654 ret = -EINVAL; 655 goto out; 656 } 657 658 skip_cow: 659 ret = -ENOMEM; 660 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 661 if (!tmp) 662 goto out; 663 664 ESP_SKB_CB(skb)->tmp = tmp; 665 seqhi = esp_tmp_seqhi(tmp); 666 iv = esp_tmp_iv(aead, tmp, seqhilen); 667 req = esp_tmp_req(aead, iv); 668 sg = esp_req_sg(aead, req); 669 670 esp_input_set_header(skb, seqhi); 671 672 sg_init_table(sg, nfrags); 673 ret = skb_to_sgvec(skb, sg, 0, skb->len); 674 if (unlikely(ret < 0)) { 675 kfree(tmp); 676 goto out; 677 } 678 679 skb->ip_summed = CHECKSUM_NONE; 680 681 if ((x->props.flags & XFRM_STATE_ESN)) 682 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 683 else 684 aead_request_set_callback(req, 0, esp_input_done, skb); 685 686 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 687 aead_request_set_ad(req, assoclen); 688 689 ret = crypto_aead_decrypt(req); 690 if (ret == -EINPROGRESS) 691 goto out; 692 693 if ((x->props.flags & XFRM_STATE_ESN)) 694 esp_input_restore_header(skb); 695 696 ret = esp6_input_done2(skb, ret); 697 698 out: 699 return ret; 700 } 701 702 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu) 703 { 704 struct crypto_aead *aead = x->data; 705 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 706 unsigned int net_adj; 707 708 if (x->props.mode != XFRM_MODE_TUNNEL) 709 net_adj = sizeof(struct ipv6hdr); 710 else 711 net_adj = 0; 712 713 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - 714 net_adj) & ~(blksize - 1)) + net_adj - 2; 715 } 716 717 static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 718 u8 type, u8 code, int offset, __be32 info) 719 { 720 struct net *net = dev_net(skb->dev); 721 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 722 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset); 723 struct xfrm_state *x; 724 725 if (type != ICMPV6_PKT_TOOBIG && 726 type != NDISC_REDIRECT) 727 return 0; 728 729 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 730 esph->spi, IPPROTO_ESP, AF_INET6); 731 if (!x) 732 return 0; 733 734 if (type == NDISC_REDIRECT) 735 ip6_redirect(skb, net, skb->dev->ifindex, 0, 736 sock_net_uid(net, NULL)); 737 else 738 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 739 xfrm_state_put(x); 740 741 return 0; 742 } 743 744 static void esp6_destroy(struct xfrm_state *x) 745 { 746 struct crypto_aead *aead = x->data; 747 748 if (!aead) 749 return; 750 751 crypto_free_aead(aead); 752 } 753 754 static int esp_init_aead(struct xfrm_state *x) 755 { 756 char aead_name[CRYPTO_MAX_ALG_NAME]; 757 struct crypto_aead *aead; 758 int err; 759 760 err = -ENAMETOOLONG; 761 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 762 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 763 goto error; 764 765 aead = crypto_alloc_aead(aead_name, 0, 0); 766 err = PTR_ERR(aead); 767 if (IS_ERR(aead)) 768 goto error; 769 770 x->data = aead; 771 772 err = crypto_aead_setkey(aead, x->aead->alg_key, 773 (x->aead->alg_key_len + 7) / 8); 774 if (err) 775 goto error; 776 777 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 778 if (err) 779 goto error; 780 781 error: 782 return err; 783 } 784 785 static int esp_init_authenc(struct xfrm_state *x) 786 { 787 struct crypto_aead *aead; 788 struct crypto_authenc_key_param *param; 789 struct rtattr *rta; 790 char *key; 791 char *p; 792 char authenc_name[CRYPTO_MAX_ALG_NAME]; 793 unsigned int keylen; 794 int err; 795 796 err = -EINVAL; 797 if (!x->ealg) 798 goto error; 799 800 err = -ENAMETOOLONG; 801 802 if ((x->props.flags & XFRM_STATE_ESN)) { 803 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 804 "%s%sauthencesn(%s,%s)%s", 805 x->geniv ?: "", x->geniv ? "(" : "", 806 x->aalg ? x->aalg->alg_name : "digest_null", 807 x->ealg->alg_name, 808 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 809 goto error; 810 } else { 811 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 812 "%s%sauthenc(%s,%s)%s", 813 x->geniv ?: "", x->geniv ? "(" : "", 814 x->aalg ? x->aalg->alg_name : "digest_null", 815 x->ealg->alg_name, 816 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 817 goto error; 818 } 819 820 aead = crypto_alloc_aead(authenc_name, 0, 0); 821 err = PTR_ERR(aead); 822 if (IS_ERR(aead)) 823 goto error; 824 825 x->data = aead; 826 827 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 828 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 829 err = -ENOMEM; 830 key = kmalloc(keylen, GFP_KERNEL); 831 if (!key) 832 goto error; 833 834 p = key; 835 rta = (void *)p; 836 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 837 rta->rta_len = RTA_LENGTH(sizeof(*param)); 838 param = RTA_DATA(rta); 839 p += RTA_SPACE(sizeof(*param)); 840 841 if (x->aalg) { 842 struct xfrm_algo_desc *aalg_desc; 843 844 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 845 p += (x->aalg->alg_key_len + 7) / 8; 846 847 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 848 BUG_ON(!aalg_desc); 849 850 err = -EINVAL; 851 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 852 crypto_aead_authsize(aead)) { 853 pr_info("ESP: %s digestsize %u != %hu\n", 854 x->aalg->alg_name, 855 crypto_aead_authsize(aead), 856 aalg_desc->uinfo.auth.icv_fullbits / 8); 857 goto free_key; 858 } 859 860 err = crypto_aead_setauthsize( 861 aead, x->aalg->alg_trunc_len / 8); 862 if (err) 863 goto free_key; 864 } 865 866 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 867 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 868 869 err = crypto_aead_setkey(aead, key, keylen); 870 871 free_key: 872 kfree(key); 873 874 error: 875 return err; 876 } 877 878 static int esp6_init_state(struct xfrm_state *x) 879 { 880 struct crypto_aead *aead; 881 u32 align; 882 int err; 883 884 if (x->encap) 885 return -EINVAL; 886 887 x->data = NULL; 888 889 if (x->aead) 890 err = esp_init_aead(x); 891 else 892 err = esp_init_authenc(x); 893 894 if (err) 895 goto error; 896 897 aead = x->data; 898 899 x->props.header_len = sizeof(struct ip_esp_hdr) + 900 crypto_aead_ivsize(aead); 901 switch (x->props.mode) { 902 case XFRM_MODE_BEET: 903 if (x->sel.family != AF_INET6) 904 x->props.header_len += IPV4_BEET_PHMAXLEN + 905 (sizeof(struct ipv6hdr) - sizeof(struct iphdr)); 906 break; 907 default: 908 case XFRM_MODE_TRANSPORT: 909 break; 910 case XFRM_MODE_TUNNEL: 911 x->props.header_len += sizeof(struct ipv6hdr); 912 break; 913 } 914 915 align = ALIGN(crypto_aead_blocksize(aead), 4); 916 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 917 918 error: 919 return err; 920 } 921 922 static int esp6_rcv_cb(struct sk_buff *skb, int err) 923 { 924 return 0; 925 } 926 927 static const struct xfrm_type esp6_type = { 928 .description = "ESP6", 929 .owner = THIS_MODULE, 930 .proto = IPPROTO_ESP, 931 .flags = XFRM_TYPE_REPLAY_PROT, 932 .init_state = esp6_init_state, 933 .destructor = esp6_destroy, 934 .get_mtu = esp6_get_mtu, 935 .input = esp6_input, 936 .output = esp6_output, 937 .hdr_offset = xfrm6_find_1stfragopt, 938 }; 939 940 static struct xfrm6_protocol esp6_protocol = { 941 .handler = xfrm6_rcv, 942 .cb_handler = esp6_rcv_cb, 943 .err_handler = esp6_err, 944 .priority = 0, 945 }; 946 947 static int __init esp6_init(void) 948 { 949 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) { 950 pr_info("%s: can't add xfrm type\n", __func__); 951 return -EAGAIN; 952 } 953 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) { 954 pr_info("%s: can't add protocol\n", __func__); 955 xfrm_unregister_type(&esp6_type, AF_INET6); 956 return -EAGAIN; 957 } 958 959 return 0; 960 } 961 962 static void __exit esp6_fini(void) 963 { 964 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0) 965 pr_info("%s: can't remove protocol\n", __func__); 966 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0) 967 pr_info("%s: can't remove xfrm type\n", __func__); 968 } 969 970 module_init(esp6_init); 971 module_exit(esp6_fini); 972 973 MODULE_LICENSE("GPL"); 974 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP); 975