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 struct xfrm_offload *xo = xfrm_offload(skb); 125 void *tmp; 126 struct xfrm_state *x; 127 128 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 129 struct sec_path *sp = skb_sec_path(skb); 130 131 x = sp->xvec[sp->len - 1]; 132 } else { 133 x = skb_dst(skb)->xfrm; 134 } 135 136 tmp = ESP_SKB_CB(skb)->tmp; 137 esp_ssg_unref(x, tmp); 138 kfree(tmp); 139 140 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 141 if (err) { 142 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 143 kfree_skb(skb); 144 return; 145 } 146 147 skb_push(skb, skb->data - skb_mac_header(skb)); 148 secpath_reset(skb); 149 xfrm_dev_resume(skb); 150 } else { 151 xfrm_output_resume(skb, err); 152 } 153 } 154 155 /* Move ESP header back into place. */ 156 static void esp_restore_header(struct sk_buff *skb, unsigned int offset) 157 { 158 struct ip_esp_hdr *esph = (void *)(skb->data + offset); 159 void *tmp = ESP_SKB_CB(skb)->tmp; 160 __be32 *seqhi = esp_tmp_extra(tmp); 161 162 esph->seq_no = esph->spi; 163 esph->spi = *seqhi; 164 } 165 166 static void esp_output_restore_header(struct sk_buff *skb) 167 { 168 void *tmp = ESP_SKB_CB(skb)->tmp; 169 struct esp_output_extra *extra = esp_tmp_extra(tmp); 170 171 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - 172 sizeof(__be32)); 173 } 174 175 static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb, 176 struct xfrm_state *x, 177 struct ip_esp_hdr *esph, 178 struct esp_output_extra *extra) 179 { 180 /* For ESN we move the header forward by 4 bytes to 181 * accomodate the high bits. We will move it back after 182 * encryption. 183 */ 184 if ((x->props.flags & XFRM_STATE_ESN)) { 185 __u32 seqhi; 186 struct xfrm_offload *xo = xfrm_offload(skb); 187 188 if (xo) 189 seqhi = xo->seq.hi; 190 else 191 seqhi = XFRM_SKB_CB(skb)->seq.output.hi; 192 193 extra->esphoff = (unsigned char *)esph - 194 skb_transport_header(skb); 195 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); 196 extra->seqhi = esph->spi; 197 esph->seq_no = htonl(seqhi); 198 } 199 200 esph->spi = x->id.spi; 201 202 return esph; 203 } 204 205 static void esp_output_done_esn(struct crypto_async_request *base, int err) 206 { 207 struct sk_buff *skb = base->data; 208 209 esp_output_restore_header(skb); 210 esp_output_done(base, err); 211 } 212 213 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) 214 { 215 /* Fill padding... */ 216 if (tfclen) { 217 memset(tail, 0, tfclen); 218 tail += tfclen; 219 } 220 do { 221 int i; 222 for (i = 0; i < plen - 2; i++) 223 tail[i] = i + 1; 224 } while (0); 225 tail[plen - 2] = plen - 2; 226 tail[plen - 1] = proto; 227 } 228 229 static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 230 { 231 int encap_type; 232 struct udphdr *uh; 233 __be32 *udpdata32; 234 __be16 sport, dport; 235 struct xfrm_encap_tmpl *encap = x->encap; 236 struct ip_esp_hdr *esph = esp->esph; 237 238 spin_lock_bh(&x->lock); 239 sport = encap->encap_sport; 240 dport = encap->encap_dport; 241 encap_type = encap->encap_type; 242 spin_unlock_bh(&x->lock); 243 244 uh = (struct udphdr *)esph; 245 uh->source = sport; 246 uh->dest = dport; 247 uh->len = htons(skb->len + esp->tailen 248 - skb_transport_offset(skb)); 249 uh->check = 0; 250 251 switch (encap_type) { 252 default: 253 case UDP_ENCAP_ESPINUDP: 254 esph = (struct ip_esp_hdr *)(uh + 1); 255 break; 256 case UDP_ENCAP_ESPINUDP_NON_IKE: 257 udpdata32 = (__be32 *)(uh + 1); 258 udpdata32[0] = udpdata32[1] = 0; 259 esph = (struct ip_esp_hdr *)(udpdata32 + 2); 260 break; 261 } 262 263 *skb_mac_header(skb) = IPPROTO_UDP; 264 esp->esph = esph; 265 } 266 267 int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 268 { 269 u8 *tail; 270 u8 *vaddr; 271 int nfrags; 272 int esph_offset; 273 struct page *page; 274 struct sk_buff *trailer; 275 int tailen = esp->tailen; 276 277 /* this is non-NULL only with UDP Encapsulation */ 278 if (x->encap) 279 esp_output_udp_encap(x, skb, esp); 280 281 if (!skb_cloned(skb)) { 282 if (tailen <= skb_tailroom(skb)) { 283 nfrags = 1; 284 trailer = skb; 285 tail = skb_tail_pointer(trailer); 286 287 goto skip_cow; 288 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) 289 && !skb_has_frag_list(skb)) { 290 int allocsize; 291 struct sock *sk = skb->sk; 292 struct page_frag *pfrag = &x->xfrag; 293 294 esp->inplace = false; 295 296 allocsize = ALIGN(tailen, L1_CACHE_BYTES); 297 298 spin_lock_bh(&x->lock); 299 300 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 301 spin_unlock_bh(&x->lock); 302 goto cow; 303 } 304 305 page = pfrag->page; 306 get_page(page); 307 308 vaddr = kmap_atomic(page); 309 310 tail = vaddr + pfrag->offset; 311 312 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 313 314 kunmap_atomic(vaddr); 315 316 nfrags = skb_shinfo(skb)->nr_frags; 317 318 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, 319 tailen); 320 skb_shinfo(skb)->nr_frags = ++nfrags; 321 322 pfrag->offset = pfrag->offset + allocsize; 323 324 spin_unlock_bh(&x->lock); 325 326 nfrags++; 327 328 skb->len += tailen; 329 skb->data_len += tailen; 330 skb->truesize += tailen; 331 if (sk) 332 refcount_add(tailen, &sk->sk_wmem_alloc); 333 334 goto out; 335 } 336 } 337 338 cow: 339 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); 340 341 nfrags = skb_cow_data(skb, tailen, &trailer); 342 if (nfrags < 0) 343 goto out; 344 tail = skb_tail_pointer(trailer); 345 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); 346 347 skip_cow: 348 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 349 pskb_put(skb, trailer, tailen); 350 351 out: 352 return nfrags; 353 } 354 EXPORT_SYMBOL_GPL(esp_output_head); 355 356 int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 357 { 358 u8 *iv; 359 int alen; 360 void *tmp; 361 int ivlen; 362 int assoclen; 363 int extralen; 364 struct page *page; 365 struct ip_esp_hdr *esph; 366 struct crypto_aead *aead; 367 struct aead_request *req; 368 struct scatterlist *sg, *dsg; 369 struct esp_output_extra *extra; 370 int err = -ENOMEM; 371 372 assoclen = sizeof(struct ip_esp_hdr); 373 extralen = 0; 374 375 if (x->props.flags & XFRM_STATE_ESN) { 376 extralen += sizeof(*extra); 377 assoclen += sizeof(__be32); 378 } 379 380 aead = x->data; 381 alen = crypto_aead_authsize(aead); 382 ivlen = crypto_aead_ivsize(aead); 383 384 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); 385 if (!tmp) 386 goto error; 387 388 extra = esp_tmp_extra(tmp); 389 iv = esp_tmp_iv(aead, tmp, extralen); 390 req = esp_tmp_req(aead, iv); 391 sg = esp_req_sg(aead, req); 392 393 if (esp->inplace) 394 dsg = sg; 395 else 396 dsg = &sg[esp->nfrags]; 397 398 esph = esp_output_set_extra(skb, x, esp->esph, extra); 399 esp->esph = esph; 400 401 sg_init_table(sg, esp->nfrags); 402 err = skb_to_sgvec(skb, sg, 403 (unsigned char *)esph - skb->data, 404 assoclen + ivlen + esp->clen + alen); 405 if (unlikely(err < 0)) 406 goto error_free; 407 408 if (!esp->inplace) { 409 int allocsize; 410 struct page_frag *pfrag = &x->xfrag; 411 412 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 413 414 spin_lock_bh(&x->lock); 415 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 416 spin_unlock_bh(&x->lock); 417 goto error_free; 418 } 419 420 skb_shinfo(skb)->nr_frags = 1; 421 422 page = pfrag->page; 423 get_page(page); 424 /* replace page frags in skb with new page */ 425 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 426 pfrag->offset = pfrag->offset + allocsize; 427 spin_unlock_bh(&x->lock); 428 429 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 430 err = skb_to_sgvec(skb, dsg, 431 (unsigned char *)esph - skb->data, 432 assoclen + ivlen + esp->clen + alen); 433 if (unlikely(err < 0)) 434 goto error_free; 435 } 436 437 if ((x->props.flags & XFRM_STATE_ESN)) 438 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 439 else 440 aead_request_set_callback(req, 0, esp_output_done, skb); 441 442 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); 443 aead_request_set_ad(req, assoclen); 444 445 memset(iv, 0, ivlen); 446 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), 447 min(ivlen, 8)); 448 449 ESP_SKB_CB(skb)->tmp = tmp; 450 err = crypto_aead_encrypt(req); 451 452 switch (err) { 453 case -EINPROGRESS: 454 goto error; 455 456 case -ENOSPC: 457 err = NET_XMIT_DROP; 458 break; 459 460 case 0: 461 if ((x->props.flags & XFRM_STATE_ESN)) 462 esp_output_restore_header(skb); 463 } 464 465 if (sg != dsg) 466 esp_ssg_unref(x, tmp); 467 468 error_free: 469 kfree(tmp); 470 error: 471 return err; 472 } 473 EXPORT_SYMBOL_GPL(esp_output_tail); 474 475 static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 476 { 477 int alen; 478 int blksize; 479 struct ip_esp_hdr *esph; 480 struct crypto_aead *aead; 481 struct esp_info esp; 482 483 esp.inplace = true; 484 485 esp.proto = *skb_mac_header(skb); 486 *skb_mac_header(skb) = IPPROTO_ESP; 487 488 /* skb is pure payload to encrypt */ 489 490 aead = x->data; 491 alen = crypto_aead_authsize(aead); 492 493 esp.tfclen = 0; 494 if (x->tfcpad) { 495 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 496 u32 padto; 497 498 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); 499 if (skb->len < padto) 500 esp.tfclen = padto - skb->len; 501 } 502 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 503 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); 504 esp.plen = esp.clen - skb->len - esp.tfclen; 505 esp.tailen = esp.tfclen + esp.plen + alen; 506 507 esp.esph = ip_esp_hdr(skb); 508 509 esp.nfrags = esp_output_head(x, skb, &esp); 510 if (esp.nfrags < 0) 511 return esp.nfrags; 512 513 esph = esp.esph; 514 esph->spi = x->id.spi; 515 516 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 517 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 518 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 519 520 skb_push(skb, -skb_network_offset(skb)); 521 522 return esp_output_tail(x, skb, &esp); 523 } 524 525 static inline int esp_remove_trailer(struct sk_buff *skb) 526 { 527 struct xfrm_state *x = xfrm_input_state(skb); 528 struct xfrm_offload *xo = xfrm_offload(skb); 529 struct crypto_aead *aead = x->data; 530 int alen, hlen, elen; 531 int padlen, trimlen; 532 __wsum csumdiff; 533 u8 nexthdr[2]; 534 int ret; 535 536 alen = crypto_aead_authsize(aead); 537 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 538 elen = skb->len - hlen; 539 540 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { 541 ret = xo->proto; 542 goto out; 543 } 544 545 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2)) 546 BUG(); 547 548 ret = -EINVAL; 549 padlen = nexthdr[0]; 550 if (padlen + 2 + alen >= elen) { 551 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", 552 padlen + 2, elen - alen); 553 goto out; 554 } 555 556 trimlen = alen + padlen + 2; 557 if (skb->ip_summed == CHECKSUM_COMPLETE) { 558 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); 559 skb->csum = csum_block_sub(skb->csum, csumdiff, 560 skb->len - trimlen); 561 } 562 pskb_trim(skb, skb->len - trimlen); 563 564 ret = nexthdr[1]; 565 566 out: 567 return ret; 568 } 569 570 int esp_input_done2(struct sk_buff *skb, int err) 571 { 572 const struct iphdr *iph; 573 struct xfrm_state *x = xfrm_input_state(skb); 574 struct xfrm_offload *xo = xfrm_offload(skb); 575 struct crypto_aead *aead = x->data; 576 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 577 int ihl; 578 579 if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) 580 kfree(ESP_SKB_CB(skb)->tmp); 581 582 if (unlikely(err)) 583 goto out; 584 585 err = esp_remove_trailer(skb); 586 if (unlikely(err < 0)) 587 goto out; 588 589 iph = ip_hdr(skb); 590 ihl = iph->ihl * 4; 591 592 if (x->encap) { 593 struct xfrm_encap_tmpl *encap = x->encap; 594 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); 595 596 /* 597 * 1) if the NAT-T peer's IP or port changed then 598 * advertize the change to the keying daemon. 599 * This is an inbound SA, so just compare 600 * SRC ports. 601 */ 602 if (iph->saddr != x->props.saddr.a4 || 603 uh->source != encap->encap_sport) { 604 xfrm_address_t ipaddr; 605 606 ipaddr.a4 = iph->saddr; 607 km_new_mapping(x, &ipaddr, uh->source); 608 609 /* XXX: perhaps add an extra 610 * policy check here, to see 611 * if we should allow or 612 * reject a packet from a 613 * different source 614 * address/port. 615 */ 616 } 617 618 /* 619 * 2) ignore UDP/TCP checksums in case 620 * of NAT-T in Transport Mode, or 621 * perform other post-processing fixes 622 * as per draft-ietf-ipsec-udp-encaps-06, 623 * section 3.1.2 624 */ 625 if (x->props.mode == XFRM_MODE_TRANSPORT) 626 skb->ip_summed = CHECKSUM_UNNECESSARY; 627 } 628 629 skb_pull_rcsum(skb, hlen); 630 if (x->props.mode == XFRM_MODE_TUNNEL) 631 skb_reset_transport_header(skb); 632 else 633 skb_set_transport_header(skb, -ihl); 634 635 /* RFC4303: Drop dummy packets without any error */ 636 if (err == IPPROTO_NONE) 637 err = -EINVAL; 638 639 out: 640 return err; 641 } 642 EXPORT_SYMBOL_GPL(esp_input_done2); 643 644 static void esp_input_done(struct crypto_async_request *base, int err) 645 { 646 struct sk_buff *skb = base->data; 647 648 xfrm_input_resume(skb, esp_input_done2(skb, err)); 649 } 650 651 static void esp_input_restore_header(struct sk_buff *skb) 652 { 653 esp_restore_header(skb, 0); 654 __skb_pull(skb, 4); 655 } 656 657 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 658 { 659 struct xfrm_state *x = xfrm_input_state(skb); 660 struct ip_esp_hdr *esph; 661 662 /* For ESN we move the header forward by 4 bytes to 663 * accomodate the high bits. We will move it back after 664 * decryption. 665 */ 666 if ((x->props.flags & XFRM_STATE_ESN)) { 667 esph = skb_push(skb, 4); 668 *seqhi = esph->spi; 669 esph->spi = esph->seq_no; 670 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 671 } 672 } 673 674 static void esp_input_done_esn(struct crypto_async_request *base, int err) 675 { 676 struct sk_buff *skb = base->data; 677 678 esp_input_restore_header(skb); 679 esp_input_done(base, err); 680 } 681 682 /* 683 * Note: detecting truncated vs. non-truncated authentication data is very 684 * expensive, so we only support truncated data, which is the recommended 685 * and common case. 686 */ 687 static int esp_input(struct xfrm_state *x, struct sk_buff *skb) 688 { 689 struct crypto_aead *aead = x->data; 690 struct aead_request *req; 691 struct sk_buff *trailer; 692 int ivlen = crypto_aead_ivsize(aead); 693 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen; 694 int nfrags; 695 int assoclen; 696 int seqhilen; 697 __be32 *seqhi; 698 void *tmp; 699 u8 *iv; 700 struct scatterlist *sg; 701 int err = -EINVAL; 702 703 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) 704 goto out; 705 706 if (elen <= 0) 707 goto out; 708 709 assoclen = sizeof(struct ip_esp_hdr); 710 seqhilen = 0; 711 712 if (x->props.flags & XFRM_STATE_ESN) { 713 seqhilen += sizeof(__be32); 714 assoclen += seqhilen; 715 } 716 717 if (!skb_cloned(skb)) { 718 if (!skb_is_nonlinear(skb)) { 719 nfrags = 1; 720 721 goto skip_cow; 722 } else if (!skb_has_frag_list(skb)) { 723 nfrags = skb_shinfo(skb)->nr_frags; 724 nfrags++; 725 726 goto skip_cow; 727 } 728 } 729 730 err = skb_cow_data(skb, 0, &trailer); 731 if (err < 0) 732 goto out; 733 734 nfrags = err; 735 736 skip_cow: 737 err = -ENOMEM; 738 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 739 if (!tmp) 740 goto out; 741 742 ESP_SKB_CB(skb)->tmp = tmp; 743 seqhi = esp_tmp_extra(tmp); 744 iv = esp_tmp_iv(aead, tmp, seqhilen); 745 req = esp_tmp_req(aead, iv); 746 sg = esp_req_sg(aead, req); 747 748 esp_input_set_header(skb, seqhi); 749 750 sg_init_table(sg, nfrags); 751 err = skb_to_sgvec(skb, sg, 0, skb->len); 752 if (unlikely(err < 0)) { 753 kfree(tmp); 754 goto out; 755 } 756 757 skb->ip_summed = CHECKSUM_NONE; 758 759 if ((x->props.flags & XFRM_STATE_ESN)) 760 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 761 else 762 aead_request_set_callback(req, 0, esp_input_done, skb); 763 764 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 765 aead_request_set_ad(req, assoclen); 766 767 err = crypto_aead_decrypt(req); 768 if (err == -EINPROGRESS) 769 goto out; 770 771 if ((x->props.flags & XFRM_STATE_ESN)) 772 esp_input_restore_header(skb); 773 774 err = esp_input_done2(skb, err); 775 776 out: 777 return err; 778 } 779 780 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) 781 { 782 struct crypto_aead *aead = x->data; 783 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 784 unsigned int net_adj; 785 786 switch (x->props.mode) { 787 case XFRM_MODE_TRANSPORT: 788 case XFRM_MODE_BEET: 789 net_adj = sizeof(struct iphdr); 790 break; 791 case XFRM_MODE_TUNNEL: 792 net_adj = 0; 793 break; 794 default: 795 BUG(); 796 } 797 798 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - 799 net_adj) & ~(blksize - 1)) + net_adj - 2; 800 } 801 802 static int esp4_err(struct sk_buff *skb, u32 info) 803 { 804 struct net *net = dev_net(skb->dev); 805 const struct iphdr *iph = (const struct iphdr *)skb->data; 806 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); 807 struct xfrm_state *x; 808 809 switch (icmp_hdr(skb)->type) { 810 case ICMP_DEST_UNREACH: 811 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 812 return 0; 813 case ICMP_REDIRECT: 814 break; 815 default: 816 return 0; 817 } 818 819 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 820 esph->spi, IPPROTO_ESP, AF_INET); 821 if (!x) 822 return 0; 823 824 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) 825 ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP); 826 else 827 ipv4_redirect(skb, net, 0, IPPROTO_ESP); 828 xfrm_state_put(x); 829 830 return 0; 831 } 832 833 static void esp_destroy(struct xfrm_state *x) 834 { 835 struct crypto_aead *aead = x->data; 836 837 if (!aead) 838 return; 839 840 crypto_free_aead(aead); 841 } 842 843 static int esp_init_aead(struct xfrm_state *x) 844 { 845 char aead_name[CRYPTO_MAX_ALG_NAME]; 846 struct crypto_aead *aead; 847 int err; 848 849 err = -ENAMETOOLONG; 850 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 851 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 852 goto error; 853 854 aead = crypto_alloc_aead(aead_name, 0, 0); 855 err = PTR_ERR(aead); 856 if (IS_ERR(aead)) 857 goto error; 858 859 x->data = aead; 860 861 err = crypto_aead_setkey(aead, x->aead->alg_key, 862 (x->aead->alg_key_len + 7) / 8); 863 if (err) 864 goto error; 865 866 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 867 if (err) 868 goto error; 869 870 error: 871 return err; 872 } 873 874 static int esp_init_authenc(struct xfrm_state *x) 875 { 876 struct crypto_aead *aead; 877 struct crypto_authenc_key_param *param; 878 struct rtattr *rta; 879 char *key; 880 char *p; 881 char authenc_name[CRYPTO_MAX_ALG_NAME]; 882 unsigned int keylen; 883 int err; 884 885 err = -EINVAL; 886 if (!x->ealg) 887 goto error; 888 889 err = -ENAMETOOLONG; 890 891 if ((x->props.flags & XFRM_STATE_ESN)) { 892 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 893 "%s%sauthencesn(%s,%s)%s", 894 x->geniv ?: "", x->geniv ? "(" : "", 895 x->aalg ? x->aalg->alg_name : "digest_null", 896 x->ealg->alg_name, 897 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 898 goto error; 899 } else { 900 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 901 "%s%sauthenc(%s,%s)%s", 902 x->geniv ?: "", x->geniv ? "(" : "", 903 x->aalg ? x->aalg->alg_name : "digest_null", 904 x->ealg->alg_name, 905 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 906 goto error; 907 } 908 909 aead = crypto_alloc_aead(authenc_name, 0, 0); 910 err = PTR_ERR(aead); 911 if (IS_ERR(aead)) 912 goto error; 913 914 x->data = aead; 915 916 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 917 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 918 err = -ENOMEM; 919 key = kmalloc(keylen, GFP_KERNEL); 920 if (!key) 921 goto error; 922 923 p = key; 924 rta = (void *)p; 925 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 926 rta->rta_len = RTA_LENGTH(sizeof(*param)); 927 param = RTA_DATA(rta); 928 p += RTA_SPACE(sizeof(*param)); 929 930 if (x->aalg) { 931 struct xfrm_algo_desc *aalg_desc; 932 933 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 934 p += (x->aalg->alg_key_len + 7) / 8; 935 936 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 937 BUG_ON(!aalg_desc); 938 939 err = -EINVAL; 940 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 941 crypto_aead_authsize(aead)) { 942 pr_info("ESP: %s digestsize %u != %hu\n", 943 x->aalg->alg_name, 944 crypto_aead_authsize(aead), 945 aalg_desc->uinfo.auth.icv_fullbits / 8); 946 goto free_key; 947 } 948 949 err = crypto_aead_setauthsize( 950 aead, x->aalg->alg_trunc_len / 8); 951 if (err) 952 goto free_key; 953 } 954 955 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 956 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 957 958 err = crypto_aead_setkey(aead, key, keylen); 959 960 free_key: 961 kfree(key); 962 963 error: 964 return err; 965 } 966 967 static int esp_init_state(struct xfrm_state *x) 968 { 969 struct crypto_aead *aead; 970 u32 align; 971 int err; 972 973 x->data = NULL; 974 975 if (x->aead) 976 err = esp_init_aead(x); 977 else 978 err = esp_init_authenc(x); 979 980 if (err) 981 goto error; 982 983 aead = x->data; 984 985 x->props.header_len = sizeof(struct ip_esp_hdr) + 986 crypto_aead_ivsize(aead); 987 if (x->props.mode == XFRM_MODE_TUNNEL) 988 x->props.header_len += sizeof(struct iphdr); 989 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) 990 x->props.header_len += IPV4_BEET_PHMAXLEN; 991 if (x->encap) { 992 struct xfrm_encap_tmpl *encap = x->encap; 993 994 switch (encap->encap_type) { 995 default: 996 err = -EINVAL; 997 goto error; 998 case UDP_ENCAP_ESPINUDP: 999 x->props.header_len += sizeof(struct udphdr); 1000 break; 1001 case UDP_ENCAP_ESPINUDP_NON_IKE: 1002 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 1003 break; 1004 } 1005 } 1006 1007 align = ALIGN(crypto_aead_blocksize(aead), 4); 1008 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 1009 1010 error: 1011 return err; 1012 } 1013 1014 static int esp4_rcv_cb(struct sk_buff *skb, int err) 1015 { 1016 return 0; 1017 } 1018 1019 static const struct xfrm_type esp_type = 1020 { 1021 .description = "ESP4", 1022 .owner = THIS_MODULE, 1023 .proto = IPPROTO_ESP, 1024 .flags = XFRM_TYPE_REPLAY_PROT, 1025 .init_state = esp_init_state, 1026 .destructor = esp_destroy, 1027 .get_mtu = esp4_get_mtu, 1028 .input = esp_input, 1029 .output = esp_output, 1030 }; 1031 1032 static struct xfrm4_protocol esp4_protocol = { 1033 .handler = xfrm4_rcv, 1034 .input_handler = xfrm_input, 1035 .cb_handler = esp4_rcv_cb, 1036 .err_handler = esp4_err, 1037 .priority = 0, 1038 }; 1039 1040 static int __init esp4_init(void) 1041 { 1042 if (xfrm_register_type(&esp_type, AF_INET) < 0) { 1043 pr_info("%s: can't add xfrm type\n", __func__); 1044 return -EAGAIN; 1045 } 1046 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { 1047 pr_info("%s: can't add protocol\n", __func__); 1048 xfrm_unregister_type(&esp_type, AF_INET); 1049 return -EAGAIN; 1050 } 1051 return 0; 1052 } 1053 1054 static void __exit esp4_fini(void) 1055 { 1056 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) 1057 pr_info("%s: can't remove protocol\n", __func__); 1058 if (xfrm_unregister_type(&esp_type, AF_INET) < 0) 1059 pr_info("%s: can't remove xfrm type\n", __func__); 1060 } 1061 1062 module_init(esp4_init); 1063 module_exit(esp4_fini); 1064 MODULE_LICENSE("GPL"); 1065 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); 1066