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