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/esp.c 12 */ 13 14 #define pr_fmt(fmt) "IPv6: " fmt 15 16 #include <crypto/aead.h> 17 #include <crypto/authenc.h> 18 #include <linux/err.h> 19 #include <linux/module.h> 20 #include <net/ip.h> 21 #include <net/xfrm.h> 22 #include <net/esp.h> 23 #include <linux/scatterlist.h> 24 #include <linux/kernel.h> 25 #include <linux/pfkeyv2.h> 26 #include <linux/random.h> 27 #include <linux/slab.h> 28 #include <linux/spinlock.h> 29 #include <net/ip6_route.h> 30 #include <net/icmp.h> 31 #include <net/ipv6.h> 32 #include <net/protocol.h> 33 #include <linux/icmpv6.h> 34 35 #include <linux/highmem.h> 36 37 struct esp_skb_cb { 38 struct xfrm_skb_cb xfrm; 39 void *tmp; 40 }; 41 42 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) 43 44 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu); 45 46 /* 47 * Allocate an AEAD request structure with extra space for SG and IV. 48 * 49 * For alignment considerations the upper 32 bits of the sequence number are 50 * placed at the front, if present. Followed by the IV, the request and finally 51 * the SG list. 52 * 53 * TODO: Use spare space in skb for this where possible. 54 */ 55 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen) 56 { 57 unsigned int len; 58 59 len = seqihlen; 60 61 len += crypto_aead_ivsize(aead); 62 63 if (len) { 64 len += crypto_aead_alignmask(aead) & 65 ~(crypto_tfm_ctx_alignment() - 1); 66 len = ALIGN(len, crypto_tfm_ctx_alignment()); 67 } 68 69 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); 70 len = ALIGN(len, __alignof__(struct scatterlist)); 71 72 len += sizeof(struct scatterlist) * nfrags; 73 74 return kmalloc(len, GFP_ATOMIC); 75 } 76 77 static inline __be32 *esp_tmp_seqhi(void *tmp) 78 { 79 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32)); 80 } 81 82 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen) 83 { 84 return crypto_aead_ivsize(aead) ? 85 PTR_ALIGN((u8 *)tmp + seqhilen, 86 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen; 87 } 88 89 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) 90 { 91 struct aead_request *req; 92 93 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), 94 crypto_tfm_ctx_alignment()); 95 aead_request_set_tfm(req, aead); 96 return req; 97 } 98 99 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, 100 struct aead_request *req) 101 { 102 return (void *)ALIGN((unsigned long)(req + 1) + 103 crypto_aead_reqsize(aead), 104 __alignof__(struct scatterlist)); 105 } 106 107 static void esp_ssg_unref(struct xfrm_state *x, void *tmp) 108 { 109 struct crypto_aead *aead = x->data; 110 int seqhilen = 0; 111 u8 *iv; 112 struct aead_request *req; 113 struct scatterlist *sg; 114 115 if (x->props.flags & XFRM_STATE_ESN) 116 seqhilen += sizeof(__be32); 117 118 iv = esp_tmp_iv(aead, tmp, seqhilen); 119 req = esp_tmp_req(aead, iv); 120 121 /* Unref skb_frag_pages in the src scatterlist if necessary. 122 * Skip the first sg which comes from skb->data. 123 */ 124 if (req->src != req->dst) 125 for (sg = sg_next(req->src); sg; sg = sg_next(sg)) 126 put_page(sg_page(sg)); 127 } 128 129 static void esp_output_done(struct crypto_async_request *base, int err) 130 { 131 struct sk_buff *skb = base->data; 132 struct xfrm_offload *xo = xfrm_offload(skb); 133 void *tmp; 134 struct xfrm_state *x; 135 136 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 137 struct sec_path *sp = skb_sec_path(skb); 138 139 x = sp->xvec[sp->len - 1]; 140 } else { 141 x = skb_dst(skb)->xfrm; 142 } 143 144 tmp = ESP_SKB_CB(skb)->tmp; 145 esp_ssg_unref(x, tmp); 146 kfree(tmp); 147 148 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 149 if (err) { 150 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 151 kfree_skb(skb); 152 return; 153 } 154 155 skb_push(skb, skb->data - skb_mac_header(skb)); 156 secpath_reset(skb); 157 xfrm_dev_resume(skb); 158 } else { 159 xfrm_output_resume(skb, err); 160 } 161 } 162 163 /* Move ESP header back into place. */ 164 static void esp_restore_header(struct sk_buff *skb, unsigned int offset) 165 { 166 struct ip_esp_hdr *esph = (void *)(skb->data + offset); 167 void *tmp = ESP_SKB_CB(skb)->tmp; 168 __be32 *seqhi = esp_tmp_seqhi(tmp); 169 170 esph->seq_no = esph->spi; 171 esph->spi = *seqhi; 172 } 173 174 static void esp_output_restore_header(struct sk_buff *skb) 175 { 176 esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32)); 177 } 178 179 static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb, 180 struct xfrm_state *x, 181 struct ip_esp_hdr *esph, 182 __be32 *seqhi) 183 { 184 /* For ESN we move the header forward by 4 bytes to 185 * accomodate the high bits. We will move it back after 186 * encryption. 187 */ 188 if ((x->props.flags & XFRM_STATE_ESN)) { 189 struct xfrm_offload *xo = xfrm_offload(skb); 190 191 esph = (void *)(skb_transport_header(skb) - sizeof(__be32)); 192 *seqhi = esph->spi; 193 if (xo) 194 esph->seq_no = htonl(xo->seq.hi); 195 else 196 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi); 197 } 198 199 esph->spi = x->id.spi; 200 201 return esph; 202 } 203 204 static void esp_output_done_esn(struct crypto_async_request *base, int err) 205 { 206 struct sk_buff *skb = base->data; 207 208 esp_output_restore_header(skb); 209 esp_output_done(base, err); 210 } 211 212 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) 213 { 214 /* Fill padding... */ 215 if (tfclen) { 216 memset(tail, 0, tfclen); 217 tail += tfclen; 218 } 219 do { 220 int i; 221 for (i = 0; i < plen - 2; i++) 222 tail[i] = i + 1; 223 } while (0); 224 tail[plen - 2] = plen - 2; 225 tail[plen - 1] = proto; 226 } 227 228 int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 229 { 230 u8 *tail; 231 u8 *vaddr; 232 int nfrags; 233 struct page *page; 234 struct sk_buff *trailer; 235 int tailen = esp->tailen; 236 237 if (!skb_cloned(skb)) { 238 if (tailen <= skb_tailroom(skb)) { 239 nfrags = 1; 240 trailer = skb; 241 tail = skb_tail_pointer(trailer); 242 243 goto skip_cow; 244 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) 245 && !skb_has_frag_list(skb)) { 246 int allocsize; 247 struct sock *sk = skb->sk; 248 struct page_frag *pfrag = &x->xfrag; 249 250 esp->inplace = false; 251 252 allocsize = ALIGN(tailen, L1_CACHE_BYTES); 253 254 spin_lock_bh(&x->lock); 255 256 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 257 spin_unlock_bh(&x->lock); 258 goto cow; 259 } 260 261 page = pfrag->page; 262 get_page(page); 263 264 vaddr = kmap_atomic(page); 265 266 tail = vaddr + pfrag->offset; 267 268 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 269 270 kunmap_atomic(vaddr); 271 272 nfrags = skb_shinfo(skb)->nr_frags; 273 274 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, 275 tailen); 276 skb_shinfo(skb)->nr_frags = ++nfrags; 277 278 pfrag->offset = pfrag->offset + allocsize; 279 280 spin_unlock_bh(&x->lock); 281 282 nfrags++; 283 284 skb->len += tailen; 285 skb->data_len += tailen; 286 skb->truesize += tailen; 287 if (sk && sk_fullsock(sk)) 288 refcount_add(tailen, &sk->sk_wmem_alloc); 289 290 goto out; 291 } 292 } 293 294 cow: 295 nfrags = skb_cow_data(skb, tailen, &trailer); 296 if (nfrags < 0) 297 goto out; 298 tail = skb_tail_pointer(trailer); 299 300 skip_cow: 301 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 302 pskb_put(skb, trailer, tailen); 303 304 out: 305 return nfrags; 306 } 307 EXPORT_SYMBOL_GPL(esp6_output_head); 308 309 int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 310 { 311 u8 *iv; 312 int alen; 313 void *tmp; 314 int ivlen; 315 int assoclen; 316 int seqhilen; 317 __be32 *seqhi; 318 struct page *page; 319 struct ip_esp_hdr *esph; 320 struct aead_request *req; 321 struct crypto_aead *aead; 322 struct scatterlist *sg, *dsg; 323 int err = -ENOMEM; 324 325 assoclen = sizeof(struct ip_esp_hdr); 326 seqhilen = 0; 327 328 if (x->props.flags & XFRM_STATE_ESN) { 329 seqhilen += sizeof(__be32); 330 assoclen += sizeof(__be32); 331 } 332 333 aead = x->data; 334 alen = crypto_aead_authsize(aead); 335 ivlen = crypto_aead_ivsize(aead); 336 337 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen); 338 if (!tmp) 339 goto error; 340 341 seqhi = esp_tmp_seqhi(tmp); 342 iv = esp_tmp_iv(aead, tmp, seqhilen); 343 req = esp_tmp_req(aead, iv); 344 sg = esp_req_sg(aead, req); 345 346 if (esp->inplace) 347 dsg = sg; 348 else 349 dsg = &sg[esp->nfrags]; 350 351 esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi); 352 353 sg_init_table(sg, esp->nfrags); 354 err = skb_to_sgvec(skb, sg, 355 (unsigned char *)esph - skb->data, 356 assoclen + ivlen + esp->clen + alen); 357 if (unlikely(err < 0)) 358 goto error_free; 359 360 if (!esp->inplace) { 361 int allocsize; 362 struct page_frag *pfrag = &x->xfrag; 363 364 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 365 366 spin_lock_bh(&x->lock); 367 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 368 spin_unlock_bh(&x->lock); 369 goto error_free; 370 } 371 372 skb_shinfo(skb)->nr_frags = 1; 373 374 page = pfrag->page; 375 get_page(page); 376 /* replace page frags in skb with new page */ 377 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 378 pfrag->offset = pfrag->offset + allocsize; 379 spin_unlock_bh(&x->lock); 380 381 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 382 err = skb_to_sgvec(skb, dsg, 383 (unsigned char *)esph - skb->data, 384 assoclen + ivlen + esp->clen + alen); 385 if (unlikely(err < 0)) 386 goto error_free; 387 } 388 389 if ((x->props.flags & XFRM_STATE_ESN)) 390 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 391 else 392 aead_request_set_callback(req, 0, esp_output_done, skb); 393 394 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); 395 aead_request_set_ad(req, assoclen); 396 397 memset(iv, 0, ivlen); 398 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), 399 min(ivlen, 8)); 400 401 ESP_SKB_CB(skb)->tmp = tmp; 402 err = crypto_aead_encrypt(req); 403 404 switch (err) { 405 case -EINPROGRESS: 406 goto error; 407 408 case -ENOSPC: 409 err = NET_XMIT_DROP; 410 break; 411 412 case 0: 413 if ((x->props.flags & XFRM_STATE_ESN)) 414 esp_output_restore_header(skb); 415 } 416 417 if (sg != dsg) 418 esp_ssg_unref(x, tmp); 419 420 error_free: 421 kfree(tmp); 422 error: 423 return err; 424 } 425 EXPORT_SYMBOL_GPL(esp6_output_tail); 426 427 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) 428 { 429 int alen; 430 int blksize; 431 struct ip_esp_hdr *esph; 432 struct crypto_aead *aead; 433 struct esp_info esp; 434 435 esp.inplace = true; 436 437 esp.proto = *skb_mac_header(skb); 438 *skb_mac_header(skb) = IPPROTO_ESP; 439 440 /* skb is pure payload to encrypt */ 441 442 aead = x->data; 443 alen = crypto_aead_authsize(aead); 444 445 esp.tfclen = 0; 446 if (x->tfcpad) { 447 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 448 u32 padto; 449 450 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached)); 451 if (skb->len < padto) 452 esp.tfclen = padto - skb->len; 453 } 454 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 455 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); 456 esp.plen = esp.clen - skb->len - esp.tfclen; 457 esp.tailen = esp.tfclen + esp.plen + alen; 458 459 esp.nfrags = esp6_output_head(x, skb, &esp); 460 if (esp.nfrags < 0) 461 return esp.nfrags; 462 463 esph = ip_esp_hdr(skb); 464 esph->spi = x->id.spi; 465 466 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 467 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 468 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 469 470 skb_push(skb, -skb_network_offset(skb)); 471 472 return esp6_output_tail(x, skb, &esp); 473 } 474 475 static inline int esp_remove_trailer(struct sk_buff *skb) 476 { 477 struct xfrm_state *x = xfrm_input_state(skb); 478 struct xfrm_offload *xo = xfrm_offload(skb); 479 struct crypto_aead *aead = x->data; 480 int alen, hlen, elen; 481 int padlen, trimlen; 482 __wsum csumdiff; 483 u8 nexthdr[2]; 484 int ret; 485 486 alen = crypto_aead_authsize(aead); 487 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 488 elen = skb->len - hlen; 489 490 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { 491 ret = xo->proto; 492 goto out; 493 } 494 495 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2); 496 BUG_ON(ret); 497 498 ret = -EINVAL; 499 padlen = nexthdr[0]; 500 if (padlen + 2 + alen >= elen) { 501 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", 502 padlen + 2, elen - alen); 503 goto out; 504 } 505 506 trimlen = alen + padlen + 2; 507 if (skb->ip_summed == CHECKSUM_COMPLETE) { 508 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); 509 skb->csum = csum_block_sub(skb->csum, csumdiff, 510 skb->len - trimlen); 511 } 512 pskb_trim(skb, skb->len - trimlen); 513 514 ret = nexthdr[1]; 515 516 out: 517 return ret; 518 } 519 520 int esp6_input_done2(struct sk_buff *skb, int err) 521 { 522 struct xfrm_state *x = xfrm_input_state(skb); 523 struct xfrm_offload *xo = xfrm_offload(skb); 524 struct crypto_aead *aead = x->data; 525 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 526 int hdr_len = skb_network_header_len(skb); 527 528 if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) 529 kfree(ESP_SKB_CB(skb)->tmp); 530 531 if (unlikely(err)) 532 goto out; 533 534 err = esp_remove_trailer(skb); 535 if (unlikely(err < 0)) 536 goto out; 537 538 skb_postpull_rcsum(skb, skb_network_header(skb), 539 skb_network_header_len(skb)); 540 skb_pull_rcsum(skb, hlen); 541 if (x->props.mode == XFRM_MODE_TUNNEL) 542 skb_reset_transport_header(skb); 543 else 544 skb_set_transport_header(skb, -hdr_len); 545 546 /* RFC4303: Drop dummy packets without any error */ 547 if (err == IPPROTO_NONE) 548 err = -EINVAL; 549 550 out: 551 return err; 552 } 553 EXPORT_SYMBOL_GPL(esp6_input_done2); 554 555 static void esp_input_done(struct crypto_async_request *base, int err) 556 { 557 struct sk_buff *skb = base->data; 558 559 xfrm_input_resume(skb, esp6_input_done2(skb, err)); 560 } 561 562 static void esp_input_restore_header(struct sk_buff *skb) 563 { 564 esp_restore_header(skb, 0); 565 __skb_pull(skb, 4); 566 } 567 568 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 569 { 570 struct xfrm_state *x = xfrm_input_state(skb); 571 572 /* For ESN we move the header forward by 4 bytes to 573 * accomodate the high bits. We will move it back after 574 * decryption. 575 */ 576 if ((x->props.flags & XFRM_STATE_ESN)) { 577 struct ip_esp_hdr *esph = skb_push(skb, 4); 578 579 *seqhi = esph->spi; 580 esph->spi = esph->seq_no; 581 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 582 } 583 } 584 585 static void esp_input_done_esn(struct crypto_async_request *base, int err) 586 { 587 struct sk_buff *skb = base->data; 588 589 esp_input_restore_header(skb); 590 esp_input_done(base, err); 591 } 592 593 static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) 594 { 595 struct crypto_aead *aead = x->data; 596 struct aead_request *req; 597 struct sk_buff *trailer; 598 int ivlen = crypto_aead_ivsize(aead); 599 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen; 600 int nfrags; 601 int assoclen; 602 int seqhilen; 603 int ret = 0; 604 void *tmp; 605 __be32 *seqhi; 606 u8 *iv; 607 struct scatterlist *sg; 608 609 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) { 610 ret = -EINVAL; 611 goto out; 612 } 613 614 if (elen <= 0) { 615 ret = -EINVAL; 616 goto out; 617 } 618 619 assoclen = sizeof(struct ip_esp_hdr); 620 seqhilen = 0; 621 622 if (x->props.flags & XFRM_STATE_ESN) { 623 seqhilen += sizeof(__be32); 624 assoclen += seqhilen; 625 } 626 627 if (!skb_cloned(skb)) { 628 if (!skb_is_nonlinear(skb)) { 629 nfrags = 1; 630 631 goto skip_cow; 632 } else if (!skb_has_frag_list(skb)) { 633 nfrags = skb_shinfo(skb)->nr_frags; 634 nfrags++; 635 636 goto skip_cow; 637 } 638 } 639 640 nfrags = skb_cow_data(skb, 0, &trailer); 641 if (nfrags < 0) { 642 ret = -EINVAL; 643 goto out; 644 } 645 646 skip_cow: 647 ret = -ENOMEM; 648 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 649 if (!tmp) 650 goto out; 651 652 ESP_SKB_CB(skb)->tmp = tmp; 653 seqhi = esp_tmp_seqhi(tmp); 654 iv = esp_tmp_iv(aead, tmp, seqhilen); 655 req = esp_tmp_req(aead, iv); 656 sg = esp_req_sg(aead, req); 657 658 esp_input_set_header(skb, seqhi); 659 660 sg_init_table(sg, nfrags); 661 ret = skb_to_sgvec(skb, sg, 0, skb->len); 662 if (unlikely(ret < 0)) { 663 kfree(tmp); 664 goto out; 665 } 666 667 skb->ip_summed = CHECKSUM_NONE; 668 669 if ((x->props.flags & XFRM_STATE_ESN)) 670 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 671 else 672 aead_request_set_callback(req, 0, esp_input_done, skb); 673 674 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 675 aead_request_set_ad(req, assoclen); 676 677 ret = crypto_aead_decrypt(req); 678 if (ret == -EINPROGRESS) 679 goto out; 680 681 if ((x->props.flags & XFRM_STATE_ESN)) 682 esp_input_restore_header(skb); 683 684 ret = esp6_input_done2(skb, ret); 685 686 out: 687 return ret; 688 } 689 690 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu) 691 { 692 struct crypto_aead *aead = x->data; 693 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 694 unsigned int net_adj; 695 696 if (x->props.mode != XFRM_MODE_TUNNEL) 697 net_adj = sizeof(struct ipv6hdr); 698 else 699 net_adj = 0; 700 701 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - 702 net_adj) & ~(blksize - 1)) + net_adj - 2; 703 } 704 705 static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 706 u8 type, u8 code, int offset, __be32 info) 707 { 708 struct net *net = dev_net(skb->dev); 709 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 710 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset); 711 struct xfrm_state *x; 712 713 if (type != ICMPV6_PKT_TOOBIG && 714 type != NDISC_REDIRECT) 715 return 0; 716 717 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 718 esph->spi, IPPROTO_ESP, AF_INET6); 719 if (!x) 720 return 0; 721 722 if (type == NDISC_REDIRECT) 723 ip6_redirect(skb, net, skb->dev->ifindex, 0, 724 sock_net_uid(net, NULL)); 725 else 726 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 727 xfrm_state_put(x); 728 729 return 0; 730 } 731 732 static void esp6_destroy(struct xfrm_state *x) 733 { 734 struct crypto_aead *aead = x->data; 735 736 if (!aead) 737 return; 738 739 crypto_free_aead(aead); 740 } 741 742 static int esp_init_aead(struct xfrm_state *x) 743 { 744 char aead_name[CRYPTO_MAX_ALG_NAME]; 745 struct crypto_aead *aead; 746 int err; 747 748 err = -ENAMETOOLONG; 749 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 750 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 751 goto error; 752 753 aead = crypto_alloc_aead(aead_name, 0, 0); 754 err = PTR_ERR(aead); 755 if (IS_ERR(aead)) 756 goto error; 757 758 x->data = aead; 759 760 err = crypto_aead_setkey(aead, x->aead->alg_key, 761 (x->aead->alg_key_len + 7) / 8); 762 if (err) 763 goto error; 764 765 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 766 if (err) 767 goto error; 768 769 error: 770 return err; 771 } 772 773 static int esp_init_authenc(struct xfrm_state *x) 774 { 775 struct crypto_aead *aead; 776 struct crypto_authenc_key_param *param; 777 struct rtattr *rta; 778 char *key; 779 char *p; 780 char authenc_name[CRYPTO_MAX_ALG_NAME]; 781 unsigned int keylen; 782 int err; 783 784 err = -EINVAL; 785 if (!x->ealg) 786 goto error; 787 788 err = -ENAMETOOLONG; 789 790 if ((x->props.flags & XFRM_STATE_ESN)) { 791 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 792 "%s%sauthencesn(%s,%s)%s", 793 x->geniv ?: "", x->geniv ? "(" : "", 794 x->aalg ? x->aalg->alg_name : "digest_null", 795 x->ealg->alg_name, 796 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 797 goto error; 798 } else { 799 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 800 "%s%sauthenc(%s,%s)%s", 801 x->geniv ?: "", x->geniv ? "(" : "", 802 x->aalg ? x->aalg->alg_name : "digest_null", 803 x->ealg->alg_name, 804 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 805 goto error; 806 } 807 808 aead = crypto_alloc_aead(authenc_name, 0, 0); 809 err = PTR_ERR(aead); 810 if (IS_ERR(aead)) 811 goto error; 812 813 x->data = aead; 814 815 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 816 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 817 err = -ENOMEM; 818 key = kmalloc(keylen, GFP_KERNEL); 819 if (!key) 820 goto error; 821 822 p = key; 823 rta = (void *)p; 824 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 825 rta->rta_len = RTA_LENGTH(sizeof(*param)); 826 param = RTA_DATA(rta); 827 p += RTA_SPACE(sizeof(*param)); 828 829 if (x->aalg) { 830 struct xfrm_algo_desc *aalg_desc; 831 832 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 833 p += (x->aalg->alg_key_len + 7) / 8; 834 835 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 836 BUG_ON(!aalg_desc); 837 838 err = -EINVAL; 839 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 840 crypto_aead_authsize(aead)) { 841 pr_info("ESP: %s digestsize %u != %hu\n", 842 x->aalg->alg_name, 843 crypto_aead_authsize(aead), 844 aalg_desc->uinfo.auth.icv_fullbits / 8); 845 goto free_key; 846 } 847 848 err = crypto_aead_setauthsize( 849 aead, x->aalg->alg_trunc_len / 8); 850 if (err) 851 goto free_key; 852 } 853 854 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 855 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 856 857 err = crypto_aead_setkey(aead, key, keylen); 858 859 free_key: 860 kfree(key); 861 862 error: 863 return err; 864 } 865 866 static int esp6_init_state(struct xfrm_state *x) 867 { 868 struct crypto_aead *aead; 869 u32 align; 870 int err; 871 872 if (x->encap) 873 return -EINVAL; 874 875 x->data = NULL; 876 877 if (x->aead) 878 err = esp_init_aead(x); 879 else 880 err = esp_init_authenc(x); 881 882 if (err) 883 goto error; 884 885 aead = x->data; 886 887 x->props.header_len = sizeof(struct ip_esp_hdr) + 888 crypto_aead_ivsize(aead); 889 switch (x->props.mode) { 890 case XFRM_MODE_BEET: 891 if (x->sel.family != AF_INET6) 892 x->props.header_len += IPV4_BEET_PHMAXLEN + 893 (sizeof(struct ipv6hdr) - sizeof(struct iphdr)); 894 break; 895 default: 896 case XFRM_MODE_TRANSPORT: 897 break; 898 case XFRM_MODE_TUNNEL: 899 x->props.header_len += sizeof(struct ipv6hdr); 900 break; 901 } 902 903 align = ALIGN(crypto_aead_blocksize(aead), 4); 904 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 905 906 error: 907 return err; 908 } 909 910 static int esp6_rcv_cb(struct sk_buff *skb, int err) 911 { 912 return 0; 913 } 914 915 static const struct xfrm_type esp6_type = { 916 .description = "ESP6", 917 .owner = THIS_MODULE, 918 .proto = IPPROTO_ESP, 919 .flags = XFRM_TYPE_REPLAY_PROT, 920 .init_state = esp6_init_state, 921 .destructor = esp6_destroy, 922 .get_mtu = esp6_get_mtu, 923 .input = esp6_input, 924 .output = esp6_output, 925 .hdr_offset = xfrm6_find_1stfragopt, 926 }; 927 928 static struct xfrm6_protocol esp6_protocol = { 929 .handler = xfrm6_rcv, 930 .cb_handler = esp6_rcv_cb, 931 .err_handler = esp6_err, 932 .priority = 0, 933 }; 934 935 static int __init esp6_init(void) 936 { 937 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) { 938 pr_info("%s: can't add xfrm type\n", __func__); 939 return -EAGAIN; 940 } 941 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) { 942 pr_info("%s: can't add protocol\n", __func__); 943 xfrm_unregister_type(&esp6_type, AF_INET6); 944 return -EAGAIN; 945 } 946 947 return 0; 948 } 949 950 static void __exit esp6_fini(void) 951 { 952 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0) 953 pr_info("%s: can't remove protocol\n", __func__); 954 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0) 955 pr_info("%s: can't remove xfrm type\n", __func__); 956 } 957 958 module_init(esp6_init); 959 module_exit(esp6_fini); 960 961 MODULE_LICENSE("GPL"); 962 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP); 963