1 #define pr_fmt(fmt) "IPsec: " fmt 2 3 #include <crypto/aead.h> 4 #include <crypto/authenc.h> 5 #include <linux/err.h> 6 #include <linux/module.h> 7 #include <net/ip.h> 8 #include <net/xfrm.h> 9 #include <net/esp.h> 10 #include <linux/scatterlist.h> 11 #include <linux/kernel.h> 12 #include <linux/pfkeyv2.h> 13 #include <linux/rtnetlink.h> 14 #include <linux/slab.h> 15 #include <linux/spinlock.h> 16 #include <linux/in6.h> 17 #include <net/icmp.h> 18 #include <net/protocol.h> 19 #include <net/udp.h> 20 21 #include <linux/highmem.h> 22 23 struct esp_skb_cb { 24 struct xfrm_skb_cb xfrm; 25 void *tmp; 26 }; 27 28 struct esp_output_extra { 29 __be32 seqhi; 30 u32 esphoff; 31 }; 32 33 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) 34 35 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu); 36 37 /* 38 * Allocate an AEAD request structure with extra space for SG and IV. 39 * 40 * For alignment considerations the IV is placed at the front, followed 41 * by the request and finally the SG list. 42 * 43 * TODO: Use spare space in skb for this where possible. 44 */ 45 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen) 46 { 47 unsigned int len; 48 49 len = extralen; 50 51 len += crypto_aead_ivsize(aead); 52 53 if (len) { 54 len += crypto_aead_alignmask(aead) & 55 ~(crypto_tfm_ctx_alignment() - 1); 56 len = ALIGN(len, crypto_tfm_ctx_alignment()); 57 } 58 59 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); 60 len = ALIGN(len, __alignof__(struct scatterlist)); 61 62 len += sizeof(struct scatterlist) * nfrags; 63 64 return kmalloc(len, GFP_ATOMIC); 65 } 66 67 static inline void *esp_tmp_extra(void *tmp) 68 { 69 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra)); 70 } 71 72 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen) 73 { 74 return crypto_aead_ivsize(aead) ? 75 PTR_ALIGN((u8 *)tmp + extralen, 76 crypto_aead_alignmask(aead) + 1) : tmp + extralen; 77 } 78 79 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) 80 { 81 struct aead_request *req; 82 83 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), 84 crypto_tfm_ctx_alignment()); 85 aead_request_set_tfm(req, aead); 86 return req; 87 } 88 89 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, 90 struct aead_request *req) 91 { 92 return (void *)ALIGN((unsigned long)(req + 1) + 93 crypto_aead_reqsize(aead), 94 __alignof__(struct scatterlist)); 95 } 96 97 static void esp_ssg_unref(struct xfrm_state *x, void *tmp) 98 { 99 struct esp_output_extra *extra = esp_tmp_extra(tmp); 100 struct crypto_aead *aead = x->data; 101 int extralen = 0; 102 u8 *iv; 103 struct aead_request *req; 104 struct scatterlist *sg; 105 106 if (x->props.flags & XFRM_STATE_ESN) 107 extralen += sizeof(*extra); 108 109 extra = esp_tmp_extra(tmp); 110 iv = esp_tmp_iv(aead, tmp, extralen); 111 req = esp_tmp_req(aead, iv); 112 113 /* Unref skb_frag_pages in the src scatterlist if necessary. 114 * Skip the first sg which comes from skb->data. 115 */ 116 if (req->src != req->dst) 117 for (sg = sg_next(req->src); sg; sg = sg_next(sg)) 118 put_page(sg_page(sg)); 119 } 120 121 static void esp_output_done(struct crypto_async_request *base, int err) 122 { 123 struct sk_buff *skb = base->data; 124 void *tmp; 125 struct dst_entry *dst = skb_dst(skb); 126 struct xfrm_state *x = dst->xfrm; 127 128 tmp = ESP_SKB_CB(skb)->tmp; 129 esp_ssg_unref(x, tmp); 130 kfree(tmp); 131 xfrm_output_resume(skb, err); 132 } 133 134 /* Move ESP header back into place. */ 135 static void esp_restore_header(struct sk_buff *skb, unsigned int offset) 136 { 137 struct ip_esp_hdr *esph = (void *)(skb->data + offset); 138 void *tmp = ESP_SKB_CB(skb)->tmp; 139 __be32 *seqhi = esp_tmp_extra(tmp); 140 141 esph->seq_no = esph->spi; 142 esph->spi = *seqhi; 143 } 144 145 static void esp_output_restore_header(struct sk_buff *skb) 146 { 147 void *tmp = ESP_SKB_CB(skb)->tmp; 148 struct esp_output_extra *extra = esp_tmp_extra(tmp); 149 150 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - 151 sizeof(__be32)); 152 } 153 154 static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb, 155 struct xfrm_state *x, 156 struct ip_esp_hdr *esph, 157 struct esp_output_extra *extra) 158 { 159 /* For ESN we move the header forward by 4 bytes to 160 * accomodate the high bits. We will move it back after 161 * encryption. 162 */ 163 if ((x->props.flags & XFRM_STATE_ESN)) { 164 __u32 seqhi; 165 struct xfrm_offload *xo = xfrm_offload(skb); 166 167 if (xo) 168 seqhi = xo->seq.hi; 169 else 170 seqhi = XFRM_SKB_CB(skb)->seq.output.hi; 171 172 extra->esphoff = (unsigned char *)esph - 173 skb_transport_header(skb); 174 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); 175 extra->seqhi = esph->spi; 176 esph->seq_no = htonl(seqhi); 177 } 178 179 esph->spi = x->id.spi; 180 181 return esph; 182 } 183 184 static void esp_output_done_esn(struct crypto_async_request *base, int err) 185 { 186 struct sk_buff *skb = base->data; 187 188 esp_output_restore_header(skb); 189 esp_output_done(base, err); 190 } 191 192 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) 193 { 194 /* Fill padding... */ 195 if (tfclen) { 196 memset(tail, 0, tfclen); 197 tail += tfclen; 198 } 199 do { 200 int i; 201 for (i = 0; i < plen - 2; i++) 202 tail[i] = i + 1; 203 } while (0); 204 tail[plen - 2] = plen - 2; 205 tail[plen - 1] = proto; 206 } 207 208 static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 209 { 210 int encap_type; 211 struct udphdr *uh; 212 __be32 *udpdata32; 213 __be16 sport, dport; 214 struct xfrm_encap_tmpl *encap = x->encap; 215 struct ip_esp_hdr *esph = esp->esph; 216 217 spin_lock_bh(&x->lock); 218 sport = encap->encap_sport; 219 dport = encap->encap_dport; 220 encap_type = encap->encap_type; 221 spin_unlock_bh(&x->lock); 222 223 uh = (struct udphdr *)esph; 224 uh->source = sport; 225 uh->dest = dport; 226 uh->len = htons(skb->len + esp->tailen 227 - skb_transport_offset(skb)); 228 uh->check = 0; 229 230 switch (encap_type) { 231 default: 232 case UDP_ENCAP_ESPINUDP: 233 esph = (struct ip_esp_hdr *)(uh + 1); 234 break; 235 case UDP_ENCAP_ESPINUDP_NON_IKE: 236 udpdata32 = (__be32 *)(uh + 1); 237 udpdata32[0] = udpdata32[1] = 0; 238 esph = (struct ip_esp_hdr *)(udpdata32 + 2); 239 break; 240 } 241 242 *skb_mac_header(skb) = IPPROTO_UDP; 243 esp->esph = esph; 244 } 245 246 int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 247 { 248 u8 *tail; 249 u8 *vaddr; 250 int nfrags; 251 int esph_offset; 252 struct page *page; 253 struct sk_buff *trailer; 254 int tailen = esp->tailen; 255 256 /* this is non-NULL only with UDP Encapsulation */ 257 if (x->encap) 258 esp_output_udp_encap(x, skb, esp); 259 260 if (!skb_cloned(skb)) { 261 if (tailen <= skb_tailroom(skb)) { 262 nfrags = 1; 263 trailer = skb; 264 tail = skb_tail_pointer(trailer); 265 266 goto skip_cow; 267 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) 268 && !skb_has_frag_list(skb)) { 269 int allocsize; 270 struct sock *sk = skb->sk; 271 struct page_frag *pfrag = &x->xfrag; 272 273 esp->inplace = false; 274 275 allocsize = ALIGN(tailen, L1_CACHE_BYTES); 276 277 spin_lock_bh(&x->lock); 278 279 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 280 spin_unlock_bh(&x->lock); 281 goto cow; 282 } 283 284 page = pfrag->page; 285 get_page(page); 286 287 vaddr = kmap_atomic(page); 288 289 tail = vaddr + pfrag->offset; 290 291 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 292 293 kunmap_atomic(vaddr); 294 295 nfrags = skb_shinfo(skb)->nr_frags; 296 297 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, 298 tailen); 299 skb_shinfo(skb)->nr_frags = ++nfrags; 300 301 pfrag->offset = pfrag->offset + allocsize; 302 303 spin_unlock_bh(&x->lock); 304 305 nfrags++; 306 307 skb->len += tailen; 308 skb->data_len += tailen; 309 skb->truesize += tailen; 310 if (sk) 311 refcount_add(tailen, &sk->sk_wmem_alloc); 312 313 goto out; 314 } 315 } 316 317 cow: 318 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); 319 320 nfrags = skb_cow_data(skb, tailen, &trailer); 321 if (nfrags < 0) 322 goto out; 323 tail = skb_tail_pointer(trailer); 324 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); 325 326 skip_cow: 327 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 328 pskb_put(skb, trailer, tailen); 329 330 out: 331 return nfrags; 332 } 333 EXPORT_SYMBOL_GPL(esp_output_head); 334 335 int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 336 { 337 u8 *iv; 338 int alen; 339 void *tmp; 340 int ivlen; 341 int assoclen; 342 int extralen; 343 struct page *page; 344 struct ip_esp_hdr *esph; 345 struct crypto_aead *aead; 346 struct aead_request *req; 347 struct scatterlist *sg, *dsg; 348 struct esp_output_extra *extra; 349 int err = -ENOMEM; 350 351 assoclen = sizeof(struct ip_esp_hdr); 352 extralen = 0; 353 354 if (x->props.flags & XFRM_STATE_ESN) { 355 extralen += sizeof(*extra); 356 assoclen += sizeof(__be32); 357 } 358 359 aead = x->data; 360 alen = crypto_aead_authsize(aead); 361 ivlen = crypto_aead_ivsize(aead); 362 363 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); 364 if (!tmp) 365 goto error; 366 367 extra = esp_tmp_extra(tmp); 368 iv = esp_tmp_iv(aead, tmp, extralen); 369 req = esp_tmp_req(aead, iv); 370 sg = esp_req_sg(aead, req); 371 372 if (esp->inplace) 373 dsg = sg; 374 else 375 dsg = &sg[esp->nfrags]; 376 377 esph = esp_output_set_extra(skb, x, esp->esph, extra); 378 esp->esph = esph; 379 380 sg_init_table(sg, esp->nfrags); 381 err = skb_to_sgvec(skb, sg, 382 (unsigned char *)esph - skb->data, 383 assoclen + ivlen + esp->clen + alen); 384 if (unlikely(err < 0)) 385 goto error_free; 386 387 if (!esp->inplace) { 388 int allocsize; 389 struct page_frag *pfrag = &x->xfrag; 390 391 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 392 393 spin_lock_bh(&x->lock); 394 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 395 spin_unlock_bh(&x->lock); 396 goto error_free; 397 } 398 399 skb_shinfo(skb)->nr_frags = 1; 400 401 page = pfrag->page; 402 get_page(page); 403 /* replace page frags in skb with new page */ 404 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 405 pfrag->offset = pfrag->offset + allocsize; 406 spin_unlock_bh(&x->lock); 407 408 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 409 err = skb_to_sgvec(skb, dsg, 410 (unsigned char *)esph - skb->data, 411 assoclen + ivlen + esp->clen + alen); 412 if (unlikely(err < 0)) 413 goto error_free; 414 } 415 416 if ((x->props.flags & XFRM_STATE_ESN)) 417 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 418 else 419 aead_request_set_callback(req, 0, esp_output_done, skb); 420 421 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); 422 aead_request_set_ad(req, assoclen); 423 424 memset(iv, 0, ivlen); 425 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), 426 min(ivlen, 8)); 427 428 ESP_SKB_CB(skb)->tmp = tmp; 429 err = crypto_aead_encrypt(req); 430 431 switch (err) { 432 case -EINPROGRESS: 433 goto error; 434 435 case -ENOSPC: 436 err = NET_XMIT_DROP; 437 break; 438 439 case 0: 440 if ((x->props.flags & XFRM_STATE_ESN)) 441 esp_output_restore_header(skb); 442 } 443 444 if (sg != dsg) 445 esp_ssg_unref(x, tmp); 446 447 error_free: 448 kfree(tmp); 449 error: 450 return err; 451 } 452 EXPORT_SYMBOL_GPL(esp_output_tail); 453 454 static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 455 { 456 int alen; 457 int blksize; 458 struct ip_esp_hdr *esph; 459 struct crypto_aead *aead; 460 struct esp_info esp; 461 462 esp.inplace = true; 463 464 esp.proto = *skb_mac_header(skb); 465 *skb_mac_header(skb) = IPPROTO_ESP; 466 467 /* skb is pure payload to encrypt */ 468 469 aead = x->data; 470 alen = crypto_aead_authsize(aead); 471 472 esp.tfclen = 0; 473 if (x->tfcpad) { 474 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 475 u32 padto; 476 477 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); 478 if (skb->len < padto) 479 esp.tfclen = padto - skb->len; 480 } 481 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 482 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); 483 esp.plen = esp.clen - skb->len - esp.tfclen; 484 esp.tailen = esp.tfclen + esp.plen + alen; 485 486 esp.esph = ip_esp_hdr(skb); 487 488 esp.nfrags = esp_output_head(x, skb, &esp); 489 if (esp.nfrags < 0) 490 return esp.nfrags; 491 492 esph = esp.esph; 493 esph->spi = x->id.spi; 494 495 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 496 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 497 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 498 499 skb_push(skb, -skb_network_offset(skb)); 500 501 return esp_output_tail(x, skb, &esp); 502 } 503 504 static inline int esp_remove_trailer(struct sk_buff *skb) 505 { 506 struct xfrm_state *x = xfrm_input_state(skb); 507 struct xfrm_offload *xo = xfrm_offload(skb); 508 struct crypto_aead *aead = x->data; 509 int alen, hlen, elen; 510 int padlen, trimlen; 511 __wsum csumdiff; 512 u8 nexthdr[2]; 513 int ret; 514 515 alen = crypto_aead_authsize(aead); 516 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 517 elen = skb->len - hlen; 518 519 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { 520 ret = xo->proto; 521 goto out; 522 } 523 524 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2)) 525 BUG(); 526 527 ret = -EINVAL; 528 padlen = nexthdr[0]; 529 if (padlen + 2 + alen >= elen) { 530 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", 531 padlen + 2, elen - alen); 532 goto out; 533 } 534 535 trimlen = alen + padlen + 2; 536 if (skb->ip_summed == CHECKSUM_COMPLETE) { 537 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); 538 skb->csum = csum_block_sub(skb->csum, csumdiff, 539 skb->len - trimlen); 540 } 541 pskb_trim(skb, skb->len - trimlen); 542 543 ret = nexthdr[1]; 544 545 out: 546 return ret; 547 } 548 549 int esp_input_done2(struct sk_buff *skb, int err) 550 { 551 const struct iphdr *iph; 552 struct xfrm_state *x = xfrm_input_state(skb); 553 struct xfrm_offload *xo = xfrm_offload(skb); 554 struct crypto_aead *aead = x->data; 555 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 556 int ihl; 557 558 if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) 559 kfree(ESP_SKB_CB(skb)->tmp); 560 561 if (unlikely(err)) 562 goto out; 563 564 err = esp_remove_trailer(skb); 565 if (unlikely(err < 0)) 566 goto out; 567 568 iph = ip_hdr(skb); 569 ihl = iph->ihl * 4; 570 571 if (x->encap) { 572 struct xfrm_encap_tmpl *encap = x->encap; 573 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); 574 575 /* 576 * 1) if the NAT-T peer's IP or port changed then 577 * advertize the change to the keying daemon. 578 * This is an inbound SA, so just compare 579 * SRC ports. 580 */ 581 if (iph->saddr != x->props.saddr.a4 || 582 uh->source != encap->encap_sport) { 583 xfrm_address_t ipaddr; 584 585 ipaddr.a4 = iph->saddr; 586 km_new_mapping(x, &ipaddr, uh->source); 587 588 /* XXX: perhaps add an extra 589 * policy check here, to see 590 * if we should allow or 591 * reject a packet from a 592 * different source 593 * address/port. 594 */ 595 } 596 597 /* 598 * 2) ignore UDP/TCP checksums in case 599 * of NAT-T in Transport Mode, or 600 * perform other post-processing fixes 601 * as per draft-ietf-ipsec-udp-encaps-06, 602 * section 3.1.2 603 */ 604 if (x->props.mode == XFRM_MODE_TRANSPORT) 605 skb->ip_summed = CHECKSUM_UNNECESSARY; 606 } 607 608 skb_pull_rcsum(skb, hlen); 609 if (x->props.mode == XFRM_MODE_TUNNEL) 610 skb_reset_transport_header(skb); 611 else 612 skb_set_transport_header(skb, -ihl); 613 614 /* RFC4303: Drop dummy packets without any error */ 615 if (err == IPPROTO_NONE) 616 err = -EINVAL; 617 618 out: 619 return err; 620 } 621 EXPORT_SYMBOL_GPL(esp_input_done2); 622 623 static void esp_input_done(struct crypto_async_request *base, int err) 624 { 625 struct sk_buff *skb = base->data; 626 627 xfrm_input_resume(skb, esp_input_done2(skb, err)); 628 } 629 630 static void esp_input_restore_header(struct sk_buff *skb) 631 { 632 esp_restore_header(skb, 0); 633 __skb_pull(skb, 4); 634 } 635 636 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 637 { 638 struct xfrm_state *x = xfrm_input_state(skb); 639 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)skb->data; 640 641 /* For ESN we move the header forward by 4 bytes to 642 * accomodate the high bits. We will move it back after 643 * decryption. 644 */ 645 if ((x->props.flags & XFRM_STATE_ESN)) { 646 esph = skb_push(skb, 4); 647 *seqhi = esph->spi; 648 esph->spi = esph->seq_no; 649 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 650 } 651 } 652 653 static void esp_input_done_esn(struct crypto_async_request *base, int err) 654 { 655 struct sk_buff *skb = base->data; 656 657 esp_input_restore_header(skb); 658 esp_input_done(base, err); 659 } 660 661 /* 662 * Note: detecting truncated vs. non-truncated authentication data is very 663 * expensive, so we only support truncated data, which is the recommended 664 * and common case. 665 */ 666 static int esp_input(struct xfrm_state *x, struct sk_buff *skb) 667 { 668 struct ip_esp_hdr *esph; 669 struct crypto_aead *aead = x->data; 670 struct aead_request *req; 671 struct sk_buff *trailer; 672 int ivlen = crypto_aead_ivsize(aead); 673 int elen = skb->len - sizeof(*esph) - ivlen; 674 int nfrags; 675 int assoclen; 676 int seqhilen; 677 __be32 *seqhi; 678 void *tmp; 679 u8 *iv; 680 struct scatterlist *sg; 681 int err = -EINVAL; 682 683 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) 684 goto out; 685 686 if (elen <= 0) 687 goto out; 688 689 assoclen = sizeof(*esph); 690 seqhilen = 0; 691 692 if (x->props.flags & XFRM_STATE_ESN) { 693 seqhilen += sizeof(__be32); 694 assoclen += seqhilen; 695 } 696 697 if (!skb_cloned(skb)) { 698 if (!skb_is_nonlinear(skb)) { 699 nfrags = 1; 700 701 goto skip_cow; 702 } else if (!skb_has_frag_list(skb)) { 703 nfrags = skb_shinfo(skb)->nr_frags; 704 nfrags++; 705 706 goto skip_cow; 707 } 708 } 709 710 err = skb_cow_data(skb, 0, &trailer); 711 if (err < 0) 712 goto out; 713 714 nfrags = err; 715 716 skip_cow: 717 err = -ENOMEM; 718 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 719 if (!tmp) 720 goto out; 721 722 ESP_SKB_CB(skb)->tmp = tmp; 723 seqhi = esp_tmp_extra(tmp); 724 iv = esp_tmp_iv(aead, tmp, seqhilen); 725 req = esp_tmp_req(aead, iv); 726 sg = esp_req_sg(aead, req); 727 728 esp_input_set_header(skb, seqhi); 729 730 sg_init_table(sg, nfrags); 731 err = skb_to_sgvec(skb, sg, 0, skb->len); 732 if (unlikely(err < 0)) { 733 kfree(tmp); 734 goto out; 735 } 736 737 skb->ip_summed = CHECKSUM_NONE; 738 739 if ((x->props.flags & XFRM_STATE_ESN)) 740 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 741 else 742 aead_request_set_callback(req, 0, esp_input_done, skb); 743 744 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 745 aead_request_set_ad(req, assoclen); 746 747 err = crypto_aead_decrypt(req); 748 if (err == -EINPROGRESS) 749 goto out; 750 751 if ((x->props.flags & XFRM_STATE_ESN)) 752 esp_input_restore_header(skb); 753 754 err = esp_input_done2(skb, err); 755 756 out: 757 return err; 758 } 759 760 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) 761 { 762 struct crypto_aead *aead = x->data; 763 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 764 unsigned int net_adj; 765 766 switch (x->props.mode) { 767 case XFRM_MODE_TRANSPORT: 768 case XFRM_MODE_BEET: 769 net_adj = sizeof(struct iphdr); 770 break; 771 case XFRM_MODE_TUNNEL: 772 net_adj = 0; 773 break; 774 default: 775 BUG(); 776 } 777 778 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - 779 net_adj) & ~(blksize - 1)) + net_adj - 2; 780 } 781 782 static int esp4_err(struct sk_buff *skb, u32 info) 783 { 784 struct net *net = dev_net(skb->dev); 785 const struct iphdr *iph = (const struct iphdr *)skb->data; 786 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); 787 struct xfrm_state *x; 788 789 switch (icmp_hdr(skb)->type) { 790 case ICMP_DEST_UNREACH: 791 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 792 return 0; 793 case ICMP_REDIRECT: 794 break; 795 default: 796 return 0; 797 } 798 799 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 800 esph->spi, IPPROTO_ESP, AF_INET); 801 if (!x) 802 return 0; 803 804 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) 805 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0); 806 else 807 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0); 808 xfrm_state_put(x); 809 810 return 0; 811 } 812 813 static void esp_destroy(struct xfrm_state *x) 814 { 815 struct crypto_aead *aead = x->data; 816 817 if (!aead) 818 return; 819 820 crypto_free_aead(aead); 821 } 822 823 static int esp_init_aead(struct xfrm_state *x) 824 { 825 char aead_name[CRYPTO_MAX_ALG_NAME]; 826 struct crypto_aead *aead; 827 int err; 828 u32 mask = 0; 829 830 err = -ENAMETOOLONG; 831 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 832 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 833 goto error; 834 835 if (x->xso.offload_handle) 836 mask |= CRYPTO_ALG_ASYNC; 837 838 aead = crypto_alloc_aead(aead_name, 0, mask); 839 err = PTR_ERR(aead); 840 if (IS_ERR(aead)) 841 goto error; 842 843 x->data = aead; 844 845 err = crypto_aead_setkey(aead, x->aead->alg_key, 846 (x->aead->alg_key_len + 7) / 8); 847 if (err) 848 goto error; 849 850 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 851 if (err) 852 goto error; 853 854 error: 855 return err; 856 } 857 858 static int esp_init_authenc(struct xfrm_state *x) 859 { 860 struct crypto_aead *aead; 861 struct crypto_authenc_key_param *param; 862 struct rtattr *rta; 863 char *key; 864 char *p; 865 char authenc_name[CRYPTO_MAX_ALG_NAME]; 866 unsigned int keylen; 867 int err; 868 u32 mask = 0; 869 870 err = -EINVAL; 871 if (!x->ealg) 872 goto error; 873 874 err = -ENAMETOOLONG; 875 876 if ((x->props.flags & XFRM_STATE_ESN)) { 877 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 878 "%s%sauthencesn(%s,%s)%s", 879 x->geniv ?: "", x->geniv ? "(" : "", 880 x->aalg ? x->aalg->alg_name : "digest_null", 881 x->ealg->alg_name, 882 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 883 goto error; 884 } else { 885 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 886 "%s%sauthenc(%s,%s)%s", 887 x->geniv ?: "", x->geniv ? "(" : "", 888 x->aalg ? x->aalg->alg_name : "digest_null", 889 x->ealg->alg_name, 890 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 891 goto error; 892 } 893 894 if (x->xso.offload_handle) 895 mask |= CRYPTO_ALG_ASYNC; 896 897 aead = crypto_alloc_aead(authenc_name, 0, mask); 898 err = PTR_ERR(aead); 899 if (IS_ERR(aead)) 900 goto error; 901 902 x->data = aead; 903 904 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 905 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 906 err = -ENOMEM; 907 key = kmalloc(keylen, GFP_KERNEL); 908 if (!key) 909 goto error; 910 911 p = key; 912 rta = (void *)p; 913 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 914 rta->rta_len = RTA_LENGTH(sizeof(*param)); 915 param = RTA_DATA(rta); 916 p += RTA_SPACE(sizeof(*param)); 917 918 if (x->aalg) { 919 struct xfrm_algo_desc *aalg_desc; 920 921 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 922 p += (x->aalg->alg_key_len + 7) / 8; 923 924 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 925 BUG_ON(!aalg_desc); 926 927 err = -EINVAL; 928 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 929 crypto_aead_authsize(aead)) { 930 pr_info("ESP: %s digestsize %u != %hu\n", 931 x->aalg->alg_name, 932 crypto_aead_authsize(aead), 933 aalg_desc->uinfo.auth.icv_fullbits / 8); 934 goto free_key; 935 } 936 937 err = crypto_aead_setauthsize( 938 aead, x->aalg->alg_trunc_len / 8); 939 if (err) 940 goto free_key; 941 } 942 943 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 944 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 945 946 err = crypto_aead_setkey(aead, key, keylen); 947 948 free_key: 949 kfree(key); 950 951 error: 952 return err; 953 } 954 955 static int esp_init_state(struct xfrm_state *x) 956 { 957 struct crypto_aead *aead; 958 u32 align; 959 int err; 960 961 x->data = NULL; 962 963 if (x->aead) 964 err = esp_init_aead(x); 965 else 966 err = esp_init_authenc(x); 967 968 if (err) 969 goto error; 970 971 aead = x->data; 972 973 x->props.header_len = sizeof(struct ip_esp_hdr) + 974 crypto_aead_ivsize(aead); 975 if (x->props.mode == XFRM_MODE_TUNNEL) 976 x->props.header_len += sizeof(struct iphdr); 977 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) 978 x->props.header_len += IPV4_BEET_PHMAXLEN; 979 if (x->encap) { 980 struct xfrm_encap_tmpl *encap = x->encap; 981 982 switch (encap->encap_type) { 983 default: 984 goto error; 985 case UDP_ENCAP_ESPINUDP: 986 x->props.header_len += sizeof(struct udphdr); 987 break; 988 case UDP_ENCAP_ESPINUDP_NON_IKE: 989 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 990 break; 991 } 992 } 993 994 align = ALIGN(crypto_aead_blocksize(aead), 4); 995 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 996 997 error: 998 return err; 999 } 1000 1001 static int esp4_rcv_cb(struct sk_buff *skb, int err) 1002 { 1003 return 0; 1004 } 1005 1006 static const struct xfrm_type esp_type = 1007 { 1008 .description = "ESP4", 1009 .owner = THIS_MODULE, 1010 .proto = IPPROTO_ESP, 1011 .flags = XFRM_TYPE_REPLAY_PROT, 1012 .init_state = esp_init_state, 1013 .destructor = esp_destroy, 1014 .get_mtu = esp4_get_mtu, 1015 .input = esp_input, 1016 .output = esp_output, 1017 }; 1018 1019 static struct xfrm4_protocol esp4_protocol = { 1020 .handler = xfrm4_rcv, 1021 .input_handler = xfrm_input, 1022 .cb_handler = esp4_rcv_cb, 1023 .err_handler = esp4_err, 1024 .priority = 0, 1025 }; 1026 1027 static int __init esp4_init(void) 1028 { 1029 if (xfrm_register_type(&esp_type, AF_INET) < 0) { 1030 pr_info("%s: can't add xfrm type\n", __func__); 1031 return -EAGAIN; 1032 } 1033 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { 1034 pr_info("%s: can't add protocol\n", __func__); 1035 xfrm_unregister_type(&esp_type, AF_INET); 1036 return -EAGAIN; 1037 } 1038 return 0; 1039 } 1040 1041 static void __exit esp4_fini(void) 1042 { 1043 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) 1044 pr_info("%s: can't remove protocol\n", __func__); 1045 if (xfrm_unregister_type(&esp_type, AF_INET) < 0) 1046 pr_info("%s: can't remove xfrm type\n", __func__); 1047 } 1048 1049 module_init(esp4_init); 1050 module_exit(esp4_fini); 1051 MODULE_LICENSE("GPL"); 1052 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); 1053