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 ip_esp_hdr *esph, 156 struct esp_output_extra *extra) 157 { 158 struct xfrm_state *x = skb_dst(skb)->xfrm; 159 160 /* For ESN we move the header forward by 4 bytes to 161 * accomodate the high bits. We will move it back after 162 * encryption. 163 */ 164 if ((x->props.flags & XFRM_STATE_ESN)) { 165 extra->esphoff = (unsigned char *)esph - 166 skb_transport_header(skb); 167 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); 168 extra->seqhi = esph->spi; 169 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi); 170 } 171 172 esph->spi = x->id.spi; 173 174 return esph; 175 } 176 177 static void esp_output_done_esn(struct crypto_async_request *base, int err) 178 { 179 struct sk_buff *skb = base->data; 180 181 esp_output_restore_header(skb); 182 esp_output_done(base, err); 183 } 184 185 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) 186 { 187 /* Fill padding... */ 188 if (tfclen) { 189 memset(tail, 0, tfclen); 190 tail += tfclen; 191 } 192 do { 193 int i; 194 for (i = 0; i < plen - 2; i++) 195 tail[i] = i + 1; 196 } while (0); 197 tail[plen - 2] = plen - 2; 198 tail[plen - 1] = proto; 199 } 200 201 static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 202 { 203 struct esp_output_extra *extra; 204 int err = -ENOMEM; 205 struct ip_esp_hdr *esph; 206 struct crypto_aead *aead; 207 struct aead_request *req; 208 struct scatterlist *sg, *dsg; 209 struct sk_buff *trailer; 210 struct page *page; 211 void *tmp; 212 u8 *iv; 213 u8 *tail; 214 u8 *vaddr; 215 int blksize; 216 int clen; 217 int alen; 218 int plen; 219 int ivlen; 220 int tfclen; 221 int nfrags; 222 int assoclen; 223 int extralen; 224 int tailen; 225 __be64 seqno; 226 __u8 proto = *skb_mac_header(skb); 227 228 /* skb is pure payload to encrypt */ 229 230 aead = x->data; 231 alen = crypto_aead_authsize(aead); 232 ivlen = crypto_aead_ivsize(aead); 233 234 tfclen = 0; 235 if (x->tfcpad) { 236 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 237 u32 padto; 238 239 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); 240 if (skb->len < padto) 241 tfclen = padto - skb->len; 242 } 243 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 244 clen = ALIGN(skb->len + 2 + tfclen, blksize); 245 plen = clen - skb->len - tfclen; 246 tailen = tfclen + plen + alen; 247 assoclen = sizeof(*esph); 248 extralen = 0; 249 250 if (x->props.flags & XFRM_STATE_ESN) { 251 extralen += sizeof(*extra); 252 assoclen += sizeof(__be32); 253 } 254 255 *skb_mac_header(skb) = IPPROTO_ESP; 256 esph = ip_esp_hdr(skb); 257 258 /* this is non-NULL only with UDP Encapsulation */ 259 if (x->encap) { 260 struct xfrm_encap_tmpl *encap = x->encap; 261 struct udphdr *uh; 262 __be32 *udpdata32; 263 __be16 sport, dport; 264 int encap_type; 265 266 spin_lock_bh(&x->lock); 267 sport = encap->encap_sport; 268 dport = encap->encap_dport; 269 encap_type = encap->encap_type; 270 spin_unlock_bh(&x->lock); 271 272 uh = (struct udphdr *)esph; 273 uh->source = sport; 274 uh->dest = dport; 275 uh->len = htons(skb->len + tailen 276 - skb_transport_offset(skb)); 277 uh->check = 0; 278 279 switch (encap_type) { 280 default: 281 case UDP_ENCAP_ESPINUDP: 282 esph = (struct ip_esp_hdr *)(uh + 1); 283 break; 284 case UDP_ENCAP_ESPINUDP_NON_IKE: 285 udpdata32 = (__be32 *)(uh + 1); 286 udpdata32[0] = udpdata32[1] = 0; 287 esph = (struct ip_esp_hdr *)(udpdata32 + 2); 288 break; 289 } 290 291 *skb_mac_header(skb) = IPPROTO_UDP; 292 } 293 294 if (!skb_cloned(skb)) { 295 if (tailen <= skb_availroom(skb)) { 296 nfrags = 1; 297 trailer = skb; 298 tail = skb_tail_pointer(trailer); 299 300 goto skip_cow; 301 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) 302 && !skb_has_frag_list(skb)) { 303 int allocsize; 304 struct sock *sk = skb->sk; 305 struct page_frag *pfrag = &x->xfrag; 306 307 allocsize = ALIGN(tailen, L1_CACHE_BYTES); 308 309 spin_lock_bh(&x->lock); 310 311 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 312 spin_unlock_bh(&x->lock); 313 goto cow; 314 } 315 316 page = pfrag->page; 317 get_page(page); 318 319 vaddr = kmap_atomic(page); 320 321 tail = vaddr + pfrag->offset; 322 323 esp_output_fill_trailer(tail, tfclen, plen, proto); 324 325 kunmap_atomic(vaddr); 326 327 nfrags = skb_shinfo(skb)->nr_frags; 328 329 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, 330 tailen); 331 skb_shinfo(skb)->nr_frags = ++nfrags; 332 333 pfrag->offset = pfrag->offset + allocsize; 334 nfrags++; 335 336 skb->len += tailen; 337 skb->data_len += tailen; 338 skb->truesize += tailen; 339 if (sk) 340 atomic_add(tailen, &sk->sk_wmem_alloc); 341 342 skb_push(skb, -skb_network_offset(skb)); 343 344 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 345 esph->spi = x->id.spi; 346 347 tmp = esp_alloc_tmp(aead, nfrags + 2, extralen); 348 if (!tmp) { 349 spin_unlock_bh(&x->lock); 350 err = -ENOMEM; 351 goto error; 352 } 353 354 extra = esp_tmp_extra(tmp); 355 iv = esp_tmp_iv(aead, tmp, extralen); 356 req = esp_tmp_req(aead, iv); 357 sg = esp_req_sg(aead, req); 358 dsg = &sg[nfrags]; 359 360 esph = esp_output_set_extra(skb, esph, extra); 361 362 sg_init_table(sg, nfrags); 363 skb_to_sgvec(skb, sg, 364 (unsigned char *)esph - skb->data, 365 assoclen + ivlen + clen + alen); 366 367 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 368 369 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 370 spin_unlock_bh(&x->lock); 371 err = -ENOMEM; 372 goto error; 373 } 374 375 skb_shinfo(skb)->nr_frags = 1; 376 377 page = pfrag->page; 378 get_page(page); 379 /* replace page frags in skb with new page */ 380 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 381 pfrag->offset = pfrag->offset + allocsize; 382 383 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 384 skb_to_sgvec(skb, dsg, 385 (unsigned char *)esph - skb->data, 386 assoclen + ivlen + clen + alen); 387 388 spin_unlock_bh(&x->lock); 389 390 goto skip_cow2; 391 } 392 } 393 394 cow: 395 err = skb_cow_data(skb, tailen, &trailer); 396 if (err < 0) 397 goto error; 398 nfrags = err; 399 tail = skb_tail_pointer(trailer); 400 esph = ip_esp_hdr(skb); 401 402 skip_cow: 403 esp_output_fill_trailer(tail, tfclen, plen, proto); 404 405 pskb_put(skb, trailer, clen - skb->len + alen); 406 skb_push(skb, -skb_network_offset(skb)); 407 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 408 esph->spi = x->id.spi; 409 410 tmp = esp_alloc_tmp(aead, nfrags, extralen); 411 if (!tmp) { 412 err = -ENOMEM; 413 goto error; 414 } 415 416 extra = esp_tmp_extra(tmp); 417 iv = esp_tmp_iv(aead, tmp, extralen); 418 req = esp_tmp_req(aead, iv); 419 sg = esp_req_sg(aead, req); 420 dsg = sg; 421 422 esph = esp_output_set_extra(skb, esph, extra); 423 424 sg_init_table(sg, nfrags); 425 skb_to_sgvec(skb, sg, 426 (unsigned char *)esph - skb->data, 427 assoclen + ivlen + clen + alen); 428 429 skip_cow2: 430 if ((x->props.flags & XFRM_STATE_ESN)) 431 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 432 else 433 aead_request_set_callback(req, 0, esp_output_done, skb); 434 435 aead_request_set_crypt(req, sg, dsg, ivlen + clen, iv); 436 aead_request_set_ad(req, assoclen); 437 438 seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 439 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 440 441 memset(iv, 0, ivlen); 442 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8), 443 min(ivlen, 8)); 444 445 ESP_SKB_CB(skb)->tmp = tmp; 446 err = crypto_aead_encrypt(req); 447 448 switch (err) { 449 case -EINPROGRESS: 450 goto error; 451 452 case -EBUSY: 453 err = NET_XMIT_DROP; 454 break; 455 456 case 0: 457 if ((x->props.flags & XFRM_STATE_ESN)) 458 esp_output_restore_header(skb); 459 } 460 461 if (sg != dsg) 462 esp_ssg_unref(x, tmp); 463 kfree(tmp); 464 465 error: 466 return err; 467 } 468 469 static int esp_input_done2(struct sk_buff *skb, int err) 470 { 471 const struct iphdr *iph; 472 struct xfrm_state *x = xfrm_input_state(skb); 473 struct crypto_aead *aead = x->data; 474 int alen = crypto_aead_authsize(aead); 475 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 476 int elen = skb->len - hlen; 477 int ihl; 478 u8 nexthdr[2]; 479 int padlen; 480 481 kfree(ESP_SKB_CB(skb)->tmp); 482 483 if (unlikely(err)) 484 goto out; 485 486 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) 487 BUG(); 488 489 err = -EINVAL; 490 padlen = nexthdr[0]; 491 if (padlen + 2 + alen >= elen) 492 goto out; 493 494 /* ... check padding bits here. Silly. :-) */ 495 496 iph = ip_hdr(skb); 497 ihl = iph->ihl * 4; 498 499 if (x->encap) { 500 struct xfrm_encap_tmpl *encap = x->encap; 501 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); 502 503 /* 504 * 1) if the NAT-T peer's IP or port changed then 505 * advertize the change to the keying daemon. 506 * This is an inbound SA, so just compare 507 * SRC ports. 508 */ 509 if (iph->saddr != x->props.saddr.a4 || 510 uh->source != encap->encap_sport) { 511 xfrm_address_t ipaddr; 512 513 ipaddr.a4 = iph->saddr; 514 km_new_mapping(x, &ipaddr, uh->source); 515 516 /* XXX: perhaps add an extra 517 * policy check here, to see 518 * if we should allow or 519 * reject a packet from a 520 * different source 521 * address/port. 522 */ 523 } 524 525 /* 526 * 2) ignore UDP/TCP checksums in case 527 * of NAT-T in Transport Mode, or 528 * perform other post-processing fixes 529 * as per draft-ietf-ipsec-udp-encaps-06, 530 * section 3.1.2 531 */ 532 if (x->props.mode == XFRM_MODE_TRANSPORT) 533 skb->ip_summed = CHECKSUM_UNNECESSARY; 534 } 535 536 pskb_trim(skb, skb->len - alen - padlen - 2); 537 __skb_pull(skb, hlen); 538 if (x->props.mode == XFRM_MODE_TUNNEL) 539 skb_reset_transport_header(skb); 540 else 541 skb_set_transport_header(skb, -ihl); 542 543 err = nexthdr[1]; 544 545 /* RFC4303: Drop dummy packets without any error */ 546 if (err == IPPROTO_NONE) 547 err = -EINVAL; 548 549 out: 550 return err; 551 } 552 553 static void esp_input_done(struct crypto_async_request *base, int err) 554 { 555 struct sk_buff *skb = base->data; 556 557 xfrm_input_resume(skb, esp_input_done2(skb, err)); 558 } 559 560 static void esp_input_restore_header(struct sk_buff *skb) 561 { 562 esp_restore_header(skb, 0); 563 __skb_pull(skb, 4); 564 } 565 566 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 567 { 568 struct xfrm_state *x = xfrm_input_state(skb); 569 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)skb->data; 570 571 /* For ESN we move the header forward by 4 bytes to 572 * accomodate the high bits. We will move it back after 573 * decryption. 574 */ 575 if ((x->props.flags & XFRM_STATE_ESN)) { 576 esph = (void *)skb_push(skb, 4); 577 *seqhi = esph->spi; 578 esph->spi = esph->seq_no; 579 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 580 } 581 } 582 583 static void esp_input_done_esn(struct crypto_async_request *base, int err) 584 { 585 struct sk_buff *skb = base->data; 586 587 esp_input_restore_header(skb); 588 esp_input_done(base, err); 589 } 590 591 /* 592 * Note: detecting truncated vs. non-truncated authentication data is very 593 * expensive, so we only support truncated data, which is the recommended 594 * and common case. 595 */ 596 static int esp_input(struct xfrm_state *x, struct sk_buff *skb) 597 { 598 struct ip_esp_hdr *esph; 599 struct crypto_aead *aead = x->data; 600 struct aead_request *req; 601 struct sk_buff *trailer; 602 int ivlen = crypto_aead_ivsize(aead); 603 int elen = skb->len - sizeof(*esph) - ivlen; 604 int nfrags; 605 int assoclen; 606 int seqhilen; 607 __be32 *seqhi; 608 void *tmp; 609 u8 *iv; 610 struct scatterlist *sg; 611 int err = -EINVAL; 612 613 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) 614 goto out; 615 616 if (elen <= 0) 617 goto out; 618 619 assoclen = sizeof(*esph); 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 err = skb_cow_data(skb, 0, &trailer); 641 if (err < 0) 642 goto out; 643 644 nfrags = err; 645 646 skip_cow: 647 err = -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_extra(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 skb_to_sgvec(skb, sg, 0, skb->len); 662 663 skb->ip_summed = CHECKSUM_NONE; 664 665 if ((x->props.flags & XFRM_STATE_ESN)) 666 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 667 else 668 aead_request_set_callback(req, 0, esp_input_done, skb); 669 670 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 671 aead_request_set_ad(req, assoclen); 672 673 err = crypto_aead_decrypt(req); 674 if (err == -EINPROGRESS) 675 goto out; 676 677 if ((x->props.flags & XFRM_STATE_ESN)) 678 esp_input_restore_header(skb); 679 680 err = esp_input_done2(skb, err); 681 682 out: 683 return err; 684 } 685 686 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) 687 { 688 struct crypto_aead *aead = x->data; 689 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 690 unsigned int net_adj; 691 692 switch (x->props.mode) { 693 case XFRM_MODE_TRANSPORT: 694 case XFRM_MODE_BEET: 695 net_adj = sizeof(struct iphdr); 696 break; 697 case XFRM_MODE_TUNNEL: 698 net_adj = 0; 699 break; 700 default: 701 BUG(); 702 } 703 704 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - 705 net_adj) & ~(blksize - 1)) + net_adj - 2; 706 } 707 708 static int esp4_err(struct sk_buff *skb, u32 info) 709 { 710 struct net *net = dev_net(skb->dev); 711 const struct iphdr *iph = (const struct iphdr *)skb->data; 712 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); 713 struct xfrm_state *x; 714 715 switch (icmp_hdr(skb)->type) { 716 case ICMP_DEST_UNREACH: 717 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 718 return 0; 719 case ICMP_REDIRECT: 720 break; 721 default: 722 return 0; 723 } 724 725 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 726 esph->spi, IPPROTO_ESP, AF_INET); 727 if (!x) 728 return 0; 729 730 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) 731 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0); 732 else 733 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0); 734 xfrm_state_put(x); 735 736 return 0; 737 } 738 739 static void esp_destroy(struct xfrm_state *x) 740 { 741 struct crypto_aead *aead = x->data; 742 743 if (!aead) 744 return; 745 746 crypto_free_aead(aead); 747 } 748 749 static int esp_init_aead(struct xfrm_state *x) 750 { 751 char aead_name[CRYPTO_MAX_ALG_NAME]; 752 struct crypto_aead *aead; 753 int err; 754 755 err = -ENAMETOOLONG; 756 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 757 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 758 goto error; 759 760 aead = crypto_alloc_aead(aead_name, 0, 0); 761 err = PTR_ERR(aead); 762 if (IS_ERR(aead)) 763 goto error; 764 765 x->data = aead; 766 767 err = crypto_aead_setkey(aead, x->aead->alg_key, 768 (x->aead->alg_key_len + 7) / 8); 769 if (err) 770 goto error; 771 772 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 773 if (err) 774 goto error; 775 776 error: 777 return err; 778 } 779 780 static int esp_init_authenc(struct xfrm_state *x) 781 { 782 struct crypto_aead *aead; 783 struct crypto_authenc_key_param *param; 784 struct rtattr *rta; 785 char *key; 786 char *p; 787 char authenc_name[CRYPTO_MAX_ALG_NAME]; 788 unsigned int keylen; 789 int err; 790 791 err = -EINVAL; 792 if (!x->ealg) 793 goto error; 794 795 err = -ENAMETOOLONG; 796 797 if ((x->props.flags & XFRM_STATE_ESN)) { 798 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 799 "%s%sauthencesn(%s,%s)%s", 800 x->geniv ?: "", x->geniv ? "(" : "", 801 x->aalg ? x->aalg->alg_name : "digest_null", 802 x->ealg->alg_name, 803 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 804 goto error; 805 } else { 806 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 807 "%s%sauthenc(%s,%s)%s", 808 x->geniv ?: "", x->geniv ? "(" : "", 809 x->aalg ? x->aalg->alg_name : "digest_null", 810 x->ealg->alg_name, 811 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 812 goto error; 813 } 814 815 aead = crypto_alloc_aead(authenc_name, 0, 0); 816 err = PTR_ERR(aead); 817 if (IS_ERR(aead)) 818 goto error; 819 820 x->data = aead; 821 822 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 823 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 824 err = -ENOMEM; 825 key = kmalloc(keylen, GFP_KERNEL); 826 if (!key) 827 goto error; 828 829 p = key; 830 rta = (void *)p; 831 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 832 rta->rta_len = RTA_LENGTH(sizeof(*param)); 833 param = RTA_DATA(rta); 834 p += RTA_SPACE(sizeof(*param)); 835 836 if (x->aalg) { 837 struct xfrm_algo_desc *aalg_desc; 838 839 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 840 p += (x->aalg->alg_key_len + 7) / 8; 841 842 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 843 BUG_ON(!aalg_desc); 844 845 err = -EINVAL; 846 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 847 crypto_aead_authsize(aead)) { 848 pr_info("ESP: %s digestsize %u != %hu\n", 849 x->aalg->alg_name, 850 crypto_aead_authsize(aead), 851 aalg_desc->uinfo.auth.icv_fullbits / 8); 852 goto free_key; 853 } 854 855 err = crypto_aead_setauthsize( 856 aead, x->aalg->alg_trunc_len / 8); 857 if (err) 858 goto free_key; 859 } 860 861 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 862 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 863 864 err = crypto_aead_setkey(aead, key, keylen); 865 866 free_key: 867 kfree(key); 868 869 error: 870 return err; 871 } 872 873 static int esp_init_state(struct xfrm_state *x) 874 { 875 struct crypto_aead *aead; 876 u32 align; 877 int err; 878 879 x->data = NULL; 880 881 if (x->aead) 882 err = esp_init_aead(x); 883 else 884 err = esp_init_authenc(x); 885 886 if (err) 887 goto error; 888 889 aead = x->data; 890 891 x->props.header_len = sizeof(struct ip_esp_hdr) + 892 crypto_aead_ivsize(aead); 893 if (x->props.mode == XFRM_MODE_TUNNEL) 894 x->props.header_len += sizeof(struct iphdr); 895 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) 896 x->props.header_len += IPV4_BEET_PHMAXLEN; 897 if (x->encap) { 898 struct xfrm_encap_tmpl *encap = x->encap; 899 900 switch (encap->encap_type) { 901 default: 902 goto error; 903 case UDP_ENCAP_ESPINUDP: 904 x->props.header_len += sizeof(struct udphdr); 905 break; 906 case UDP_ENCAP_ESPINUDP_NON_IKE: 907 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 908 break; 909 } 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 esp4_rcv_cb(struct sk_buff *skb, int err) 920 { 921 return 0; 922 } 923 924 static const struct xfrm_type esp_type = 925 { 926 .description = "ESP4", 927 .owner = THIS_MODULE, 928 .proto = IPPROTO_ESP, 929 .flags = XFRM_TYPE_REPLAY_PROT, 930 .init_state = esp_init_state, 931 .destructor = esp_destroy, 932 .get_mtu = esp4_get_mtu, 933 .input = esp_input, 934 .output = esp_output 935 }; 936 937 static struct xfrm4_protocol esp4_protocol = { 938 .handler = xfrm4_rcv, 939 .input_handler = xfrm_input, 940 .cb_handler = esp4_rcv_cb, 941 .err_handler = esp4_err, 942 .priority = 0, 943 }; 944 945 static int __init esp4_init(void) 946 { 947 if (xfrm_register_type(&esp_type, AF_INET) < 0) { 948 pr_info("%s: can't add xfrm type\n", __func__); 949 return -EAGAIN; 950 } 951 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { 952 pr_info("%s: can't add protocol\n", __func__); 953 xfrm_unregister_type(&esp_type, AF_INET); 954 return -EAGAIN; 955 } 956 return 0; 957 } 958 959 static void __exit esp4_fini(void) 960 { 961 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) 962 pr_info("%s: can't remove protocol\n", __func__); 963 if (xfrm_unregister_type(&esp_type, AF_INET) < 0) 964 pr_info("%s: can't remove xfrm type\n", __func__); 965 } 966 967 module_init(esp4_init); 968 module_exit(esp4_fini); 969 MODULE_LICENSE("GPL"); 970 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); 971