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_availroom(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 spin_unlock_bh(&x->lock); 296 297 nfrags = skb_shinfo(skb)->nr_frags; 298 299 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, 300 tailen); 301 skb_shinfo(skb)->nr_frags = ++nfrags; 302 303 pfrag->offset = pfrag->offset + allocsize; 304 nfrags++; 305 306 skb->len += tailen; 307 skb->data_len += tailen; 308 skb->truesize += tailen; 309 if (sk) 310 refcount_add(tailen, &sk->sk_wmem_alloc); 311 312 goto out; 313 } 314 } 315 316 cow: 317 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); 318 319 nfrags = skb_cow_data(skb, tailen, &trailer); 320 if (nfrags < 0) 321 goto out; 322 tail = skb_tail_pointer(trailer); 323 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); 324 325 skip_cow: 326 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 327 pskb_put(skb, trailer, tailen); 328 329 out: 330 return nfrags; 331 } 332 EXPORT_SYMBOL_GPL(esp_output_head); 333 334 int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 335 { 336 u8 *iv; 337 int alen; 338 void *tmp; 339 int ivlen; 340 int assoclen; 341 int extralen; 342 struct page *page; 343 struct ip_esp_hdr *esph; 344 struct crypto_aead *aead; 345 struct aead_request *req; 346 struct scatterlist *sg, *dsg; 347 struct esp_output_extra *extra; 348 int err = -ENOMEM; 349 350 assoclen = sizeof(struct ip_esp_hdr); 351 extralen = 0; 352 353 if (x->props.flags & XFRM_STATE_ESN) { 354 extralen += sizeof(*extra); 355 assoclen += sizeof(__be32); 356 } 357 358 aead = x->data; 359 alen = crypto_aead_authsize(aead); 360 ivlen = crypto_aead_ivsize(aead); 361 362 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); 363 if (!tmp) 364 goto error; 365 366 extra = esp_tmp_extra(tmp); 367 iv = esp_tmp_iv(aead, tmp, extralen); 368 req = esp_tmp_req(aead, iv); 369 sg = esp_req_sg(aead, req); 370 371 if (esp->inplace) 372 dsg = sg; 373 else 374 dsg = &sg[esp->nfrags]; 375 376 esph = esp_output_set_extra(skb, x, esp->esph, extra); 377 esp->esph = esph; 378 379 sg_init_table(sg, esp->nfrags); 380 err = skb_to_sgvec(skb, sg, 381 (unsigned char *)esph - skb->data, 382 assoclen + ivlen + esp->clen + alen); 383 if (unlikely(err < 0)) 384 goto error; 385 386 if (!esp->inplace) { 387 int allocsize; 388 struct page_frag *pfrag = &x->xfrag; 389 390 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 391 392 spin_lock_bh(&x->lock); 393 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 394 spin_unlock_bh(&x->lock); 395 goto error; 396 } 397 398 skb_shinfo(skb)->nr_frags = 1; 399 400 page = pfrag->page; 401 get_page(page); 402 /* replace page frags in skb with new page */ 403 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 404 pfrag->offset = pfrag->offset + allocsize; 405 spin_unlock_bh(&x->lock); 406 407 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 408 err = skb_to_sgvec(skb, dsg, 409 (unsigned char *)esph - skb->data, 410 assoclen + ivlen + esp->clen + alen); 411 if (unlikely(err < 0)) 412 goto error; 413 } 414 415 if ((x->props.flags & XFRM_STATE_ESN)) 416 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 417 else 418 aead_request_set_callback(req, 0, esp_output_done, skb); 419 420 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); 421 aead_request_set_ad(req, assoclen); 422 423 memset(iv, 0, ivlen); 424 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), 425 min(ivlen, 8)); 426 427 ESP_SKB_CB(skb)->tmp = tmp; 428 err = crypto_aead_encrypt(req); 429 430 switch (err) { 431 case -EINPROGRESS: 432 goto error; 433 434 case -EBUSY: 435 err = NET_XMIT_DROP; 436 break; 437 438 case 0: 439 if ((x->props.flags & XFRM_STATE_ESN)) 440 esp_output_restore_header(skb); 441 } 442 443 if (sg != dsg) 444 esp_ssg_unref(x, tmp); 445 kfree(tmp); 446 447 error: 448 return err; 449 } 450 EXPORT_SYMBOL_GPL(esp_output_tail); 451 452 static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 453 { 454 int alen; 455 int blksize; 456 struct ip_esp_hdr *esph; 457 struct crypto_aead *aead; 458 struct esp_info esp; 459 460 esp.inplace = true; 461 462 esp.proto = *skb_mac_header(skb); 463 *skb_mac_header(skb) = IPPROTO_ESP; 464 465 /* skb is pure payload to encrypt */ 466 467 aead = x->data; 468 alen = crypto_aead_authsize(aead); 469 470 esp.tfclen = 0; 471 if (x->tfcpad) { 472 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 473 u32 padto; 474 475 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); 476 if (skb->len < padto) 477 esp.tfclen = padto - skb->len; 478 } 479 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 480 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); 481 esp.plen = esp.clen - skb->len - esp.tfclen; 482 esp.tailen = esp.tfclen + esp.plen + alen; 483 484 esp.esph = ip_esp_hdr(skb); 485 486 esp.nfrags = esp_output_head(x, skb, &esp); 487 if (esp.nfrags < 0) 488 return esp.nfrags; 489 490 esph = esp.esph; 491 esph->spi = x->id.spi; 492 493 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 494 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 495 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 496 497 skb_push(skb, -skb_network_offset(skb)); 498 499 return esp_output_tail(x, skb, &esp); 500 } 501 502 int esp_input_done2(struct sk_buff *skb, int err) 503 { 504 const struct iphdr *iph; 505 struct xfrm_state *x = xfrm_input_state(skb); 506 struct xfrm_offload *xo = xfrm_offload(skb); 507 struct crypto_aead *aead = x->data; 508 int alen = crypto_aead_authsize(aead); 509 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 510 int elen = skb->len - hlen; 511 int ihl; 512 u8 nexthdr[2]; 513 int padlen; 514 515 if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) 516 kfree(ESP_SKB_CB(skb)->tmp); 517 518 if (unlikely(err)) 519 goto out; 520 521 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) 522 BUG(); 523 524 err = -EINVAL; 525 padlen = nexthdr[0]; 526 if (padlen + 2 + alen >= elen) 527 goto out; 528 529 /* ... check padding bits here. Silly. :-) */ 530 531 iph = ip_hdr(skb); 532 ihl = iph->ihl * 4; 533 534 if (x->encap) { 535 struct xfrm_encap_tmpl *encap = x->encap; 536 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); 537 538 /* 539 * 1) if the NAT-T peer's IP or port changed then 540 * advertize the change to the keying daemon. 541 * This is an inbound SA, so just compare 542 * SRC ports. 543 */ 544 if (iph->saddr != x->props.saddr.a4 || 545 uh->source != encap->encap_sport) { 546 xfrm_address_t ipaddr; 547 548 ipaddr.a4 = iph->saddr; 549 km_new_mapping(x, &ipaddr, uh->source); 550 551 /* XXX: perhaps add an extra 552 * policy check here, to see 553 * if we should allow or 554 * reject a packet from a 555 * different source 556 * address/port. 557 */ 558 } 559 560 /* 561 * 2) ignore UDP/TCP checksums in case 562 * of NAT-T in Transport Mode, or 563 * perform other post-processing fixes 564 * as per draft-ietf-ipsec-udp-encaps-06, 565 * section 3.1.2 566 */ 567 if (x->props.mode == XFRM_MODE_TRANSPORT) 568 skb->ip_summed = CHECKSUM_UNNECESSARY; 569 } 570 571 pskb_trim(skb, skb->len - alen - padlen - 2); 572 __skb_pull(skb, hlen); 573 if (x->props.mode == XFRM_MODE_TUNNEL) 574 skb_reset_transport_header(skb); 575 else 576 skb_set_transport_header(skb, -ihl); 577 578 err = nexthdr[1]; 579 580 /* RFC4303: Drop dummy packets without any error */ 581 if (err == IPPROTO_NONE) 582 err = -EINVAL; 583 584 out: 585 return err; 586 } 587 EXPORT_SYMBOL_GPL(esp_input_done2); 588 589 static void esp_input_done(struct crypto_async_request *base, int err) 590 { 591 struct sk_buff *skb = base->data; 592 593 xfrm_input_resume(skb, esp_input_done2(skb, err)); 594 } 595 596 static void esp_input_restore_header(struct sk_buff *skb) 597 { 598 esp_restore_header(skb, 0); 599 __skb_pull(skb, 4); 600 } 601 602 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 603 { 604 struct xfrm_state *x = xfrm_input_state(skb); 605 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)skb->data; 606 607 /* For ESN we move the header forward by 4 bytes to 608 * accomodate the high bits. We will move it back after 609 * decryption. 610 */ 611 if ((x->props.flags & XFRM_STATE_ESN)) { 612 esph = skb_push(skb, 4); 613 *seqhi = esph->spi; 614 esph->spi = esph->seq_no; 615 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 616 } 617 } 618 619 static void esp_input_done_esn(struct crypto_async_request *base, int err) 620 { 621 struct sk_buff *skb = base->data; 622 623 esp_input_restore_header(skb); 624 esp_input_done(base, err); 625 } 626 627 /* 628 * Note: detecting truncated vs. non-truncated authentication data is very 629 * expensive, so we only support truncated data, which is the recommended 630 * and common case. 631 */ 632 static int esp_input(struct xfrm_state *x, struct sk_buff *skb) 633 { 634 struct ip_esp_hdr *esph; 635 struct crypto_aead *aead = x->data; 636 struct aead_request *req; 637 struct sk_buff *trailer; 638 int ivlen = crypto_aead_ivsize(aead); 639 int elen = skb->len - sizeof(*esph) - ivlen; 640 int nfrags; 641 int assoclen; 642 int seqhilen; 643 __be32 *seqhi; 644 void *tmp; 645 u8 *iv; 646 struct scatterlist *sg; 647 int err = -EINVAL; 648 649 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) 650 goto out; 651 652 if (elen <= 0) 653 goto out; 654 655 assoclen = sizeof(*esph); 656 seqhilen = 0; 657 658 if (x->props.flags & XFRM_STATE_ESN) { 659 seqhilen += sizeof(__be32); 660 assoclen += seqhilen; 661 } 662 663 if (!skb_cloned(skb)) { 664 if (!skb_is_nonlinear(skb)) { 665 nfrags = 1; 666 667 goto skip_cow; 668 } else if (!skb_has_frag_list(skb)) { 669 nfrags = skb_shinfo(skb)->nr_frags; 670 nfrags++; 671 672 goto skip_cow; 673 } 674 } 675 676 err = skb_cow_data(skb, 0, &trailer); 677 if (err < 0) 678 goto out; 679 680 nfrags = err; 681 682 skip_cow: 683 err = -ENOMEM; 684 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 685 if (!tmp) 686 goto out; 687 688 ESP_SKB_CB(skb)->tmp = tmp; 689 seqhi = esp_tmp_extra(tmp); 690 iv = esp_tmp_iv(aead, tmp, seqhilen); 691 req = esp_tmp_req(aead, iv); 692 sg = esp_req_sg(aead, req); 693 694 esp_input_set_header(skb, seqhi); 695 696 sg_init_table(sg, nfrags); 697 err = skb_to_sgvec(skb, sg, 0, skb->len); 698 if (unlikely(err < 0)) 699 goto out; 700 701 skb->ip_summed = CHECKSUM_NONE; 702 703 if ((x->props.flags & XFRM_STATE_ESN)) 704 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 705 else 706 aead_request_set_callback(req, 0, esp_input_done, skb); 707 708 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 709 aead_request_set_ad(req, assoclen); 710 711 err = crypto_aead_decrypt(req); 712 if (err == -EINPROGRESS) 713 goto out; 714 715 if ((x->props.flags & XFRM_STATE_ESN)) 716 esp_input_restore_header(skb); 717 718 err = esp_input_done2(skb, err); 719 720 out: 721 return err; 722 } 723 724 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) 725 { 726 struct crypto_aead *aead = x->data; 727 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 728 unsigned int net_adj; 729 730 switch (x->props.mode) { 731 case XFRM_MODE_TRANSPORT: 732 case XFRM_MODE_BEET: 733 net_adj = sizeof(struct iphdr); 734 break; 735 case XFRM_MODE_TUNNEL: 736 net_adj = 0; 737 break; 738 default: 739 BUG(); 740 } 741 742 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - 743 net_adj) & ~(blksize - 1)) + net_adj - 2; 744 } 745 746 static int esp4_err(struct sk_buff *skb, u32 info) 747 { 748 struct net *net = dev_net(skb->dev); 749 const struct iphdr *iph = (const struct iphdr *)skb->data; 750 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); 751 struct xfrm_state *x; 752 753 switch (icmp_hdr(skb)->type) { 754 case ICMP_DEST_UNREACH: 755 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 756 return 0; 757 case ICMP_REDIRECT: 758 break; 759 default: 760 return 0; 761 } 762 763 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 764 esph->spi, IPPROTO_ESP, AF_INET); 765 if (!x) 766 return 0; 767 768 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) 769 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0); 770 else 771 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0); 772 xfrm_state_put(x); 773 774 return 0; 775 } 776 777 static void esp_destroy(struct xfrm_state *x) 778 { 779 struct crypto_aead *aead = x->data; 780 781 if (!aead) 782 return; 783 784 crypto_free_aead(aead); 785 } 786 787 static int esp_init_aead(struct xfrm_state *x) 788 { 789 char aead_name[CRYPTO_MAX_ALG_NAME]; 790 struct crypto_aead *aead; 791 int err; 792 u32 mask = 0; 793 794 err = -ENAMETOOLONG; 795 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 796 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 797 goto error; 798 799 if (x->xso.offload_handle) 800 mask |= CRYPTO_ALG_ASYNC; 801 802 aead = crypto_alloc_aead(aead_name, 0, mask); 803 err = PTR_ERR(aead); 804 if (IS_ERR(aead)) 805 goto error; 806 807 x->data = aead; 808 809 err = crypto_aead_setkey(aead, x->aead->alg_key, 810 (x->aead->alg_key_len + 7) / 8); 811 if (err) 812 goto error; 813 814 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 815 if (err) 816 goto error; 817 818 error: 819 return err; 820 } 821 822 static int esp_init_authenc(struct xfrm_state *x) 823 { 824 struct crypto_aead *aead; 825 struct crypto_authenc_key_param *param; 826 struct rtattr *rta; 827 char *key; 828 char *p; 829 char authenc_name[CRYPTO_MAX_ALG_NAME]; 830 unsigned int keylen; 831 int err; 832 u32 mask = 0; 833 834 err = -EINVAL; 835 if (!x->ealg) 836 goto error; 837 838 err = -ENAMETOOLONG; 839 840 if ((x->props.flags & XFRM_STATE_ESN)) { 841 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 842 "%s%sauthencesn(%s,%s)%s", 843 x->geniv ?: "", x->geniv ? "(" : "", 844 x->aalg ? x->aalg->alg_name : "digest_null", 845 x->ealg->alg_name, 846 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 847 goto error; 848 } else { 849 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 850 "%s%sauthenc(%s,%s)%s", 851 x->geniv ?: "", x->geniv ? "(" : "", 852 x->aalg ? x->aalg->alg_name : "digest_null", 853 x->ealg->alg_name, 854 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 855 goto error; 856 } 857 858 if (x->xso.offload_handle) 859 mask |= CRYPTO_ALG_ASYNC; 860 861 aead = crypto_alloc_aead(authenc_name, 0, mask); 862 err = PTR_ERR(aead); 863 if (IS_ERR(aead)) 864 goto error; 865 866 x->data = aead; 867 868 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 869 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 870 err = -ENOMEM; 871 key = kmalloc(keylen, GFP_KERNEL); 872 if (!key) 873 goto error; 874 875 p = key; 876 rta = (void *)p; 877 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 878 rta->rta_len = RTA_LENGTH(sizeof(*param)); 879 param = RTA_DATA(rta); 880 p += RTA_SPACE(sizeof(*param)); 881 882 if (x->aalg) { 883 struct xfrm_algo_desc *aalg_desc; 884 885 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 886 p += (x->aalg->alg_key_len + 7) / 8; 887 888 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 889 BUG_ON(!aalg_desc); 890 891 err = -EINVAL; 892 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 893 crypto_aead_authsize(aead)) { 894 pr_info("ESP: %s digestsize %u != %hu\n", 895 x->aalg->alg_name, 896 crypto_aead_authsize(aead), 897 aalg_desc->uinfo.auth.icv_fullbits / 8); 898 goto free_key; 899 } 900 901 err = crypto_aead_setauthsize( 902 aead, x->aalg->alg_trunc_len / 8); 903 if (err) 904 goto free_key; 905 } 906 907 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 908 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 909 910 err = crypto_aead_setkey(aead, key, keylen); 911 912 free_key: 913 kfree(key); 914 915 error: 916 return err; 917 } 918 919 static int esp_init_state(struct xfrm_state *x) 920 { 921 struct crypto_aead *aead; 922 u32 align; 923 int err; 924 925 x->data = NULL; 926 927 if (x->aead) 928 err = esp_init_aead(x); 929 else 930 err = esp_init_authenc(x); 931 932 if (err) 933 goto error; 934 935 aead = x->data; 936 937 x->props.header_len = sizeof(struct ip_esp_hdr) + 938 crypto_aead_ivsize(aead); 939 if (x->props.mode == XFRM_MODE_TUNNEL) 940 x->props.header_len += sizeof(struct iphdr); 941 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) 942 x->props.header_len += IPV4_BEET_PHMAXLEN; 943 if (x->encap) { 944 struct xfrm_encap_tmpl *encap = x->encap; 945 946 switch (encap->encap_type) { 947 default: 948 goto error; 949 case UDP_ENCAP_ESPINUDP: 950 x->props.header_len += sizeof(struct udphdr); 951 break; 952 case UDP_ENCAP_ESPINUDP_NON_IKE: 953 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 954 break; 955 } 956 } 957 958 align = ALIGN(crypto_aead_blocksize(aead), 4); 959 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 960 961 error: 962 return err; 963 } 964 965 static int esp4_rcv_cb(struct sk_buff *skb, int err) 966 { 967 return 0; 968 } 969 970 static const struct xfrm_type esp_type = 971 { 972 .description = "ESP4", 973 .owner = THIS_MODULE, 974 .proto = IPPROTO_ESP, 975 .flags = XFRM_TYPE_REPLAY_PROT, 976 .init_state = esp_init_state, 977 .destructor = esp_destroy, 978 .get_mtu = esp4_get_mtu, 979 .input = esp_input, 980 .output = esp_output, 981 }; 982 983 static struct xfrm4_protocol esp4_protocol = { 984 .handler = xfrm4_rcv, 985 .input_handler = xfrm_input, 986 .cb_handler = esp4_rcv_cb, 987 .err_handler = esp4_err, 988 .priority = 0, 989 }; 990 991 static int __init esp4_init(void) 992 { 993 if (xfrm_register_type(&esp_type, AF_INET) < 0) { 994 pr_info("%s: can't add xfrm type\n", __func__); 995 return -EAGAIN; 996 } 997 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { 998 pr_info("%s: can't add protocol\n", __func__); 999 xfrm_unregister_type(&esp_type, AF_INET); 1000 return -EAGAIN; 1001 } 1002 return 0; 1003 } 1004 1005 static void __exit esp4_fini(void) 1006 { 1007 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) 1008 pr_info("%s: can't remove protocol\n", __func__); 1009 if (xfrm_unregister_type(&esp_type, AF_INET) < 0) 1010 pr_info("%s: can't remove xfrm type\n", __func__); 1011 } 1012 1013 module_init(esp4_init); 1014 module_exit(esp4_fini); 1015 MODULE_LICENSE("GPL"); 1016 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); 1017