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