1 // SPDX-License-Identifier: GPL-2.0-only 2 #define pr_fmt(fmt) "IPsec: " fmt 3 4 #include <crypto/aead.h> 5 #include <crypto/authenc.h> 6 #include <linux/err.h> 7 #include <linux/module.h> 8 #include <net/ip.h> 9 #include <net/xfrm.h> 10 #include <net/esp.h> 11 #include <linux/scatterlist.h> 12 #include <linux/kernel.h> 13 #include <linux/pfkeyv2.h> 14 #include <linux/rtnetlink.h> 15 #include <linux/slab.h> 16 #include <linux/spinlock.h> 17 #include <linux/in6.h> 18 #include <net/icmp.h> 19 #include <net/protocol.h> 20 #include <net/udp.h> 21 22 #include <linux/highmem.h> 23 24 struct esp_skb_cb { 25 struct xfrm_skb_cb xfrm; 26 void *tmp; 27 }; 28 29 struct esp_output_extra { 30 __be32 seqhi; 31 u32 esphoff; 32 }; 33 34 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) 35 36 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu); 37 38 /* 39 * Allocate an AEAD request structure with extra space for SG and IV. 40 * 41 * For alignment considerations the IV is placed at the front, followed 42 * by the request and finally the SG list. 43 * 44 * TODO: Use spare space in skb for this where possible. 45 */ 46 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen) 47 { 48 unsigned int len; 49 50 len = extralen; 51 52 len += crypto_aead_ivsize(aead); 53 54 if (len) { 55 len += crypto_aead_alignmask(aead) & 56 ~(crypto_tfm_ctx_alignment() - 1); 57 len = ALIGN(len, crypto_tfm_ctx_alignment()); 58 } 59 60 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); 61 len = ALIGN(len, __alignof__(struct scatterlist)); 62 63 len += sizeof(struct scatterlist) * nfrags; 64 65 return kmalloc(len, GFP_ATOMIC); 66 } 67 68 static inline void *esp_tmp_extra(void *tmp) 69 { 70 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra)); 71 } 72 73 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen) 74 { 75 return crypto_aead_ivsize(aead) ? 76 PTR_ALIGN((u8 *)tmp + extralen, 77 crypto_aead_alignmask(aead) + 1) : tmp + extralen; 78 } 79 80 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) 81 { 82 struct aead_request *req; 83 84 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), 85 crypto_tfm_ctx_alignment()); 86 aead_request_set_tfm(req, aead); 87 return req; 88 } 89 90 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, 91 struct aead_request *req) 92 { 93 return (void *)ALIGN((unsigned long)(req + 1) + 94 crypto_aead_reqsize(aead), 95 __alignof__(struct scatterlist)); 96 } 97 98 static void esp_ssg_unref(struct xfrm_state *x, void *tmp) 99 { 100 struct esp_output_extra *extra = esp_tmp_extra(tmp); 101 struct crypto_aead *aead = x->data; 102 int extralen = 0; 103 u8 *iv; 104 struct aead_request *req; 105 struct scatterlist *sg; 106 107 if (x->props.flags & XFRM_STATE_ESN) 108 extralen += sizeof(*extra); 109 110 extra = esp_tmp_extra(tmp); 111 iv = esp_tmp_iv(aead, tmp, extralen); 112 req = esp_tmp_req(aead, iv); 113 114 /* Unref skb_frag_pages in the src scatterlist if necessary. 115 * Skip the first sg which comes from skb->data. 116 */ 117 if (req->src != req->dst) 118 for (sg = sg_next(req->src); sg; sg = sg_next(sg)) 119 put_page(sg_page(sg)); 120 } 121 122 static void esp_output_done(struct crypto_async_request *base, int err) 123 { 124 struct sk_buff *skb = base->data; 125 struct xfrm_offload *xo = xfrm_offload(skb); 126 void *tmp; 127 struct xfrm_state *x; 128 129 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 130 struct sec_path *sp = skb_sec_path(skb); 131 132 x = sp->xvec[sp->len - 1]; 133 } else { 134 x = skb_dst(skb)->xfrm; 135 } 136 137 tmp = ESP_SKB_CB(skb)->tmp; 138 esp_ssg_unref(x, tmp); 139 kfree(tmp); 140 141 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 142 if (err) { 143 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 144 kfree_skb(skb); 145 return; 146 } 147 148 skb_push(skb, skb->data - skb_mac_header(skb)); 149 secpath_reset(skb); 150 xfrm_dev_resume(skb); 151 } else { 152 xfrm_output_resume(skb, err); 153 } 154 } 155 156 /* Move ESP header back into place. */ 157 static void esp_restore_header(struct sk_buff *skb, unsigned int offset) 158 { 159 struct ip_esp_hdr *esph = (void *)(skb->data + offset); 160 void *tmp = ESP_SKB_CB(skb)->tmp; 161 __be32 *seqhi = esp_tmp_extra(tmp); 162 163 esph->seq_no = esph->spi; 164 esph->spi = *seqhi; 165 } 166 167 static void esp_output_restore_header(struct sk_buff *skb) 168 { 169 void *tmp = ESP_SKB_CB(skb)->tmp; 170 struct esp_output_extra *extra = esp_tmp_extra(tmp); 171 172 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - 173 sizeof(__be32)); 174 } 175 176 static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb, 177 struct xfrm_state *x, 178 struct ip_esp_hdr *esph, 179 struct esp_output_extra *extra) 180 { 181 /* For ESN we move the header forward by 4 bytes to 182 * accomodate the high bits. We will move it back after 183 * encryption. 184 */ 185 if ((x->props.flags & XFRM_STATE_ESN)) { 186 __u32 seqhi; 187 struct xfrm_offload *xo = xfrm_offload(skb); 188 189 if (xo) 190 seqhi = xo->seq.hi; 191 else 192 seqhi = XFRM_SKB_CB(skb)->seq.output.hi; 193 194 extra->esphoff = (unsigned char *)esph - 195 skb_transport_header(skb); 196 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); 197 extra->seqhi = esph->spi; 198 esph->seq_no = htonl(seqhi); 199 } 200 201 esph->spi = x->id.spi; 202 203 return esph; 204 } 205 206 static void esp_output_done_esn(struct crypto_async_request *base, int err) 207 { 208 struct sk_buff *skb = base->data; 209 210 esp_output_restore_header(skb); 211 esp_output_done(base, err); 212 } 213 214 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) 215 { 216 /* Fill padding... */ 217 if (tfclen) { 218 memset(tail, 0, tfclen); 219 tail += tfclen; 220 } 221 do { 222 int i; 223 for (i = 0; i < plen - 2; i++) 224 tail[i] = i + 1; 225 } while (0); 226 tail[plen - 2] = plen - 2; 227 tail[plen - 1] = proto; 228 } 229 230 static int esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 231 { 232 int encap_type; 233 struct udphdr *uh; 234 __be32 *udpdata32; 235 __be16 sport, dport; 236 struct xfrm_encap_tmpl *encap = x->encap; 237 struct ip_esp_hdr *esph = esp->esph; 238 unsigned int len; 239 240 spin_lock_bh(&x->lock); 241 sport = encap->encap_sport; 242 dport = encap->encap_dport; 243 encap_type = encap->encap_type; 244 spin_unlock_bh(&x->lock); 245 246 len = skb->len + esp->tailen - skb_transport_offset(skb); 247 if (len + sizeof(struct iphdr) >= IP_MAX_MTU) 248 return -EMSGSIZE; 249 250 uh = (struct udphdr *)esph; 251 uh->source = sport; 252 uh->dest = dport; 253 uh->len = htons(len); 254 uh->check = 0; 255 256 switch (encap_type) { 257 default: 258 case UDP_ENCAP_ESPINUDP: 259 esph = (struct ip_esp_hdr *)(uh + 1); 260 break; 261 case UDP_ENCAP_ESPINUDP_NON_IKE: 262 udpdata32 = (__be32 *)(uh + 1); 263 udpdata32[0] = udpdata32[1] = 0; 264 esph = (struct ip_esp_hdr *)(udpdata32 + 2); 265 break; 266 } 267 268 *skb_mac_header(skb) = IPPROTO_UDP; 269 esp->esph = esph; 270 271 return 0; 272 } 273 274 int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 275 { 276 u8 *tail; 277 u8 *vaddr; 278 int nfrags; 279 int esph_offset; 280 struct page *page; 281 struct sk_buff *trailer; 282 int tailen = esp->tailen; 283 284 /* this is non-NULL only with UDP Encapsulation */ 285 if (x->encap) { 286 int err = esp_output_udp_encap(x, skb, esp); 287 288 if (err < 0) 289 return err; 290 } 291 292 if (!skb_cloned(skb)) { 293 if (tailen <= skb_tailroom(skb)) { 294 nfrags = 1; 295 trailer = skb; 296 tail = skb_tail_pointer(trailer); 297 298 goto skip_cow; 299 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) 300 && !skb_has_frag_list(skb)) { 301 int allocsize; 302 struct sock *sk = skb->sk; 303 struct page_frag *pfrag = &x->xfrag; 304 305 esp->inplace = false; 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, esp->tfclen, esp->plen, esp->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; 334 335 spin_unlock_bh(&x->lock); 336 337 nfrags++; 338 339 skb->len += tailen; 340 skb->data_len += tailen; 341 skb->truesize += tailen; 342 if (sk && sk_fullsock(sk)) 343 refcount_add(tailen, &sk->sk_wmem_alloc); 344 345 goto out; 346 } 347 } 348 349 cow: 350 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); 351 352 nfrags = skb_cow_data(skb, tailen, &trailer); 353 if (nfrags < 0) 354 goto out; 355 tail = skb_tail_pointer(trailer); 356 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); 357 358 skip_cow: 359 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 360 pskb_put(skb, trailer, tailen); 361 362 out: 363 return nfrags; 364 } 365 EXPORT_SYMBOL_GPL(esp_output_head); 366 367 int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 368 { 369 u8 *iv; 370 int alen; 371 void *tmp; 372 int ivlen; 373 int assoclen; 374 int extralen; 375 struct page *page; 376 struct ip_esp_hdr *esph; 377 struct crypto_aead *aead; 378 struct aead_request *req; 379 struct scatterlist *sg, *dsg; 380 struct esp_output_extra *extra; 381 int err = -ENOMEM; 382 383 assoclen = sizeof(struct ip_esp_hdr); 384 extralen = 0; 385 386 if (x->props.flags & XFRM_STATE_ESN) { 387 extralen += sizeof(*extra); 388 assoclen += sizeof(__be32); 389 } 390 391 aead = x->data; 392 alen = crypto_aead_authsize(aead); 393 ivlen = crypto_aead_ivsize(aead); 394 395 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); 396 if (!tmp) 397 goto error; 398 399 extra = esp_tmp_extra(tmp); 400 iv = esp_tmp_iv(aead, tmp, extralen); 401 req = esp_tmp_req(aead, iv); 402 sg = esp_req_sg(aead, req); 403 404 if (esp->inplace) 405 dsg = sg; 406 else 407 dsg = &sg[esp->nfrags]; 408 409 esph = esp_output_set_extra(skb, x, esp->esph, extra); 410 esp->esph = esph; 411 412 sg_init_table(sg, esp->nfrags); 413 err = skb_to_sgvec(skb, sg, 414 (unsigned char *)esph - skb->data, 415 assoclen + ivlen + esp->clen + alen); 416 if (unlikely(err < 0)) 417 goto error_free; 418 419 if (!esp->inplace) { 420 int allocsize; 421 struct page_frag *pfrag = &x->xfrag; 422 423 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 424 425 spin_lock_bh(&x->lock); 426 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 427 spin_unlock_bh(&x->lock); 428 goto error_free; 429 } 430 431 skb_shinfo(skb)->nr_frags = 1; 432 433 page = pfrag->page; 434 get_page(page); 435 /* replace page frags in skb with new page */ 436 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 437 pfrag->offset = pfrag->offset + allocsize; 438 spin_unlock_bh(&x->lock); 439 440 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 441 err = skb_to_sgvec(skb, dsg, 442 (unsigned char *)esph - skb->data, 443 assoclen + ivlen + esp->clen + alen); 444 if (unlikely(err < 0)) 445 goto error_free; 446 } 447 448 if ((x->props.flags & XFRM_STATE_ESN)) 449 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 450 else 451 aead_request_set_callback(req, 0, esp_output_done, skb); 452 453 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); 454 aead_request_set_ad(req, assoclen); 455 456 memset(iv, 0, ivlen); 457 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), 458 min(ivlen, 8)); 459 460 ESP_SKB_CB(skb)->tmp = tmp; 461 err = crypto_aead_encrypt(req); 462 463 switch (err) { 464 case -EINPROGRESS: 465 goto error; 466 467 case -ENOSPC: 468 err = NET_XMIT_DROP; 469 break; 470 471 case 0: 472 if ((x->props.flags & XFRM_STATE_ESN)) 473 esp_output_restore_header(skb); 474 } 475 476 if (sg != dsg) 477 esp_ssg_unref(x, tmp); 478 479 error_free: 480 kfree(tmp); 481 error: 482 return err; 483 } 484 EXPORT_SYMBOL_GPL(esp_output_tail); 485 486 static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 487 { 488 int alen; 489 int blksize; 490 struct ip_esp_hdr *esph; 491 struct crypto_aead *aead; 492 struct esp_info esp; 493 494 esp.inplace = true; 495 496 esp.proto = *skb_mac_header(skb); 497 *skb_mac_header(skb) = IPPROTO_ESP; 498 499 /* skb is pure payload to encrypt */ 500 501 aead = x->data; 502 alen = crypto_aead_authsize(aead); 503 504 esp.tfclen = 0; 505 if (x->tfcpad) { 506 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 507 u32 padto; 508 509 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); 510 if (skb->len < padto) 511 esp.tfclen = padto - skb->len; 512 } 513 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 514 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); 515 esp.plen = esp.clen - skb->len - esp.tfclen; 516 esp.tailen = esp.tfclen + esp.plen + alen; 517 518 esp.esph = ip_esp_hdr(skb); 519 520 esp.nfrags = esp_output_head(x, skb, &esp); 521 if (esp.nfrags < 0) 522 return esp.nfrags; 523 524 esph = esp.esph; 525 esph->spi = x->id.spi; 526 527 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 528 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 529 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 530 531 skb_push(skb, -skb_network_offset(skb)); 532 533 return esp_output_tail(x, skb, &esp); 534 } 535 536 static inline int esp_remove_trailer(struct sk_buff *skb) 537 { 538 struct xfrm_state *x = xfrm_input_state(skb); 539 struct xfrm_offload *xo = xfrm_offload(skb); 540 struct crypto_aead *aead = x->data; 541 int alen, hlen, elen; 542 int padlen, trimlen; 543 __wsum csumdiff; 544 u8 nexthdr[2]; 545 int ret; 546 547 alen = crypto_aead_authsize(aead); 548 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 549 elen = skb->len - hlen; 550 551 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { 552 ret = xo->proto; 553 goto out; 554 } 555 556 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2)) 557 BUG(); 558 559 ret = -EINVAL; 560 padlen = nexthdr[0]; 561 if (padlen + 2 + alen >= elen) { 562 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", 563 padlen + 2, elen - alen); 564 goto out; 565 } 566 567 trimlen = alen + padlen + 2; 568 if (skb->ip_summed == CHECKSUM_COMPLETE) { 569 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); 570 skb->csum = csum_block_sub(skb->csum, csumdiff, 571 skb->len - trimlen); 572 } 573 pskb_trim(skb, skb->len - trimlen); 574 575 ret = nexthdr[1]; 576 577 out: 578 return ret; 579 } 580 581 int esp_input_done2(struct sk_buff *skb, int err) 582 { 583 const struct iphdr *iph; 584 struct xfrm_state *x = xfrm_input_state(skb); 585 struct xfrm_offload *xo = xfrm_offload(skb); 586 struct crypto_aead *aead = x->data; 587 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 588 int ihl; 589 590 if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) 591 kfree(ESP_SKB_CB(skb)->tmp); 592 593 if (unlikely(err)) 594 goto out; 595 596 err = esp_remove_trailer(skb); 597 if (unlikely(err < 0)) 598 goto out; 599 600 iph = ip_hdr(skb); 601 ihl = iph->ihl * 4; 602 603 if (x->encap) { 604 struct xfrm_encap_tmpl *encap = x->encap; 605 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); 606 607 /* 608 * 1) if the NAT-T peer's IP or port changed then 609 * advertize the change to the keying daemon. 610 * This is an inbound SA, so just compare 611 * SRC ports. 612 */ 613 if (iph->saddr != x->props.saddr.a4 || 614 uh->source != encap->encap_sport) { 615 xfrm_address_t ipaddr; 616 617 ipaddr.a4 = iph->saddr; 618 km_new_mapping(x, &ipaddr, uh->source); 619 620 /* XXX: perhaps add an extra 621 * policy check here, to see 622 * if we should allow or 623 * reject a packet from a 624 * different source 625 * address/port. 626 */ 627 } 628 629 /* 630 * 2) ignore UDP/TCP checksums in case 631 * of NAT-T in Transport Mode, or 632 * perform other post-processing fixes 633 * as per draft-ietf-ipsec-udp-encaps-06, 634 * section 3.1.2 635 */ 636 if (x->props.mode == XFRM_MODE_TRANSPORT) 637 skb->ip_summed = CHECKSUM_UNNECESSARY; 638 } 639 640 skb_pull_rcsum(skb, hlen); 641 if (x->props.mode == XFRM_MODE_TUNNEL) 642 skb_reset_transport_header(skb); 643 else 644 skb_set_transport_header(skb, -ihl); 645 646 /* RFC4303: Drop dummy packets without any error */ 647 if (err == IPPROTO_NONE) 648 err = -EINVAL; 649 650 out: 651 return err; 652 } 653 EXPORT_SYMBOL_GPL(esp_input_done2); 654 655 static void esp_input_done(struct crypto_async_request *base, int err) 656 { 657 struct sk_buff *skb = base->data; 658 659 xfrm_input_resume(skb, esp_input_done2(skb, err)); 660 } 661 662 static void esp_input_restore_header(struct sk_buff *skb) 663 { 664 esp_restore_header(skb, 0); 665 __skb_pull(skb, 4); 666 } 667 668 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 669 { 670 struct xfrm_state *x = xfrm_input_state(skb); 671 struct ip_esp_hdr *esph; 672 673 /* For ESN we move the header forward by 4 bytes to 674 * accomodate the high bits. We will move it back after 675 * decryption. 676 */ 677 if ((x->props.flags & XFRM_STATE_ESN)) { 678 esph = skb_push(skb, 4); 679 *seqhi = esph->spi; 680 esph->spi = esph->seq_no; 681 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 682 } 683 } 684 685 static void esp_input_done_esn(struct crypto_async_request *base, int err) 686 { 687 struct sk_buff *skb = base->data; 688 689 esp_input_restore_header(skb); 690 esp_input_done(base, err); 691 } 692 693 /* 694 * Note: detecting truncated vs. non-truncated authentication data is very 695 * expensive, so we only support truncated data, which is the recommended 696 * and common case. 697 */ 698 static int esp_input(struct xfrm_state *x, struct sk_buff *skb) 699 { 700 struct crypto_aead *aead = x->data; 701 struct aead_request *req; 702 struct sk_buff *trailer; 703 int ivlen = crypto_aead_ivsize(aead); 704 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen; 705 int nfrags; 706 int assoclen; 707 int seqhilen; 708 __be32 *seqhi; 709 void *tmp; 710 u8 *iv; 711 struct scatterlist *sg; 712 int err = -EINVAL; 713 714 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) 715 goto out; 716 717 if (elen <= 0) 718 goto out; 719 720 assoclen = sizeof(struct ip_esp_hdr); 721 seqhilen = 0; 722 723 if (x->props.flags & XFRM_STATE_ESN) { 724 seqhilen += sizeof(__be32); 725 assoclen += seqhilen; 726 } 727 728 if (!skb_cloned(skb)) { 729 if (!skb_is_nonlinear(skb)) { 730 nfrags = 1; 731 732 goto skip_cow; 733 } else if (!skb_has_frag_list(skb)) { 734 nfrags = skb_shinfo(skb)->nr_frags; 735 nfrags++; 736 737 goto skip_cow; 738 } 739 } 740 741 err = skb_cow_data(skb, 0, &trailer); 742 if (err < 0) 743 goto out; 744 745 nfrags = err; 746 747 skip_cow: 748 err = -ENOMEM; 749 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 750 if (!tmp) 751 goto out; 752 753 ESP_SKB_CB(skb)->tmp = tmp; 754 seqhi = esp_tmp_extra(tmp); 755 iv = esp_tmp_iv(aead, tmp, seqhilen); 756 req = esp_tmp_req(aead, iv); 757 sg = esp_req_sg(aead, req); 758 759 esp_input_set_header(skb, seqhi); 760 761 sg_init_table(sg, nfrags); 762 err = skb_to_sgvec(skb, sg, 0, skb->len); 763 if (unlikely(err < 0)) { 764 kfree(tmp); 765 goto out; 766 } 767 768 skb->ip_summed = CHECKSUM_NONE; 769 770 if ((x->props.flags & XFRM_STATE_ESN)) 771 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 772 else 773 aead_request_set_callback(req, 0, esp_input_done, skb); 774 775 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 776 aead_request_set_ad(req, assoclen); 777 778 err = crypto_aead_decrypt(req); 779 if (err == -EINPROGRESS) 780 goto out; 781 782 if ((x->props.flags & XFRM_STATE_ESN)) 783 esp_input_restore_header(skb); 784 785 err = esp_input_done2(skb, err); 786 787 out: 788 return err; 789 } 790 791 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) 792 { 793 struct crypto_aead *aead = x->data; 794 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 795 unsigned int net_adj; 796 797 switch (x->props.mode) { 798 case XFRM_MODE_TRANSPORT: 799 case XFRM_MODE_BEET: 800 net_adj = sizeof(struct iphdr); 801 break; 802 case XFRM_MODE_TUNNEL: 803 net_adj = 0; 804 break; 805 default: 806 BUG(); 807 } 808 809 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - 810 net_adj) & ~(blksize - 1)) + net_adj - 2; 811 } 812 813 static int esp4_err(struct sk_buff *skb, u32 info) 814 { 815 struct net *net = dev_net(skb->dev); 816 const struct iphdr *iph = (const struct iphdr *)skb->data; 817 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); 818 struct xfrm_state *x; 819 820 switch (icmp_hdr(skb)->type) { 821 case ICMP_DEST_UNREACH: 822 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 823 return 0; 824 case ICMP_REDIRECT: 825 break; 826 default: 827 return 0; 828 } 829 830 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 831 esph->spi, IPPROTO_ESP, AF_INET); 832 if (!x) 833 return 0; 834 835 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) 836 ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP); 837 else 838 ipv4_redirect(skb, net, 0, IPPROTO_ESP); 839 xfrm_state_put(x); 840 841 return 0; 842 } 843 844 static void esp_destroy(struct xfrm_state *x) 845 { 846 struct crypto_aead *aead = x->data; 847 848 if (!aead) 849 return; 850 851 crypto_free_aead(aead); 852 } 853 854 static int esp_init_aead(struct xfrm_state *x) 855 { 856 char aead_name[CRYPTO_MAX_ALG_NAME]; 857 struct crypto_aead *aead; 858 int err; 859 860 err = -ENAMETOOLONG; 861 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 862 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 863 goto error; 864 865 aead = crypto_alloc_aead(aead_name, 0, 0); 866 err = PTR_ERR(aead); 867 if (IS_ERR(aead)) 868 goto error; 869 870 x->data = aead; 871 872 err = crypto_aead_setkey(aead, x->aead->alg_key, 873 (x->aead->alg_key_len + 7) / 8); 874 if (err) 875 goto error; 876 877 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 878 if (err) 879 goto error; 880 881 error: 882 return err; 883 } 884 885 static int esp_init_authenc(struct xfrm_state *x) 886 { 887 struct crypto_aead *aead; 888 struct crypto_authenc_key_param *param; 889 struct rtattr *rta; 890 char *key; 891 char *p; 892 char authenc_name[CRYPTO_MAX_ALG_NAME]; 893 unsigned int keylen; 894 int err; 895 896 err = -EINVAL; 897 if (!x->ealg) 898 goto error; 899 900 err = -ENAMETOOLONG; 901 902 if ((x->props.flags & XFRM_STATE_ESN)) { 903 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 904 "%s%sauthencesn(%s,%s)%s", 905 x->geniv ?: "", x->geniv ? "(" : "", 906 x->aalg ? x->aalg->alg_name : "digest_null", 907 x->ealg->alg_name, 908 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 909 goto error; 910 } else { 911 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 912 "%s%sauthenc(%s,%s)%s", 913 x->geniv ?: "", x->geniv ? "(" : "", 914 x->aalg ? x->aalg->alg_name : "digest_null", 915 x->ealg->alg_name, 916 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 917 goto error; 918 } 919 920 aead = crypto_alloc_aead(authenc_name, 0, 0); 921 err = PTR_ERR(aead); 922 if (IS_ERR(aead)) 923 goto error; 924 925 x->data = aead; 926 927 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 928 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 929 err = -ENOMEM; 930 key = kmalloc(keylen, GFP_KERNEL); 931 if (!key) 932 goto error; 933 934 p = key; 935 rta = (void *)p; 936 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 937 rta->rta_len = RTA_LENGTH(sizeof(*param)); 938 param = RTA_DATA(rta); 939 p += RTA_SPACE(sizeof(*param)); 940 941 if (x->aalg) { 942 struct xfrm_algo_desc *aalg_desc; 943 944 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 945 p += (x->aalg->alg_key_len + 7) / 8; 946 947 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 948 BUG_ON(!aalg_desc); 949 950 err = -EINVAL; 951 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 952 crypto_aead_authsize(aead)) { 953 pr_info("ESP: %s digestsize %u != %hu\n", 954 x->aalg->alg_name, 955 crypto_aead_authsize(aead), 956 aalg_desc->uinfo.auth.icv_fullbits / 8); 957 goto free_key; 958 } 959 960 err = crypto_aead_setauthsize( 961 aead, x->aalg->alg_trunc_len / 8); 962 if (err) 963 goto free_key; 964 } 965 966 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 967 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 968 969 err = crypto_aead_setkey(aead, key, keylen); 970 971 free_key: 972 kfree(key); 973 974 error: 975 return err; 976 } 977 978 static int esp_init_state(struct xfrm_state *x) 979 { 980 struct crypto_aead *aead; 981 u32 align; 982 int err; 983 984 x->data = NULL; 985 986 if (x->aead) 987 err = esp_init_aead(x); 988 else 989 err = esp_init_authenc(x); 990 991 if (err) 992 goto error; 993 994 aead = x->data; 995 996 x->props.header_len = sizeof(struct ip_esp_hdr) + 997 crypto_aead_ivsize(aead); 998 if (x->props.mode == XFRM_MODE_TUNNEL) 999 x->props.header_len += sizeof(struct iphdr); 1000 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) 1001 x->props.header_len += IPV4_BEET_PHMAXLEN; 1002 if (x->encap) { 1003 struct xfrm_encap_tmpl *encap = x->encap; 1004 1005 switch (encap->encap_type) { 1006 default: 1007 err = -EINVAL; 1008 goto error; 1009 case UDP_ENCAP_ESPINUDP: 1010 x->props.header_len += sizeof(struct udphdr); 1011 break; 1012 case UDP_ENCAP_ESPINUDP_NON_IKE: 1013 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 1014 break; 1015 } 1016 } 1017 1018 align = ALIGN(crypto_aead_blocksize(aead), 4); 1019 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 1020 1021 error: 1022 return err; 1023 } 1024 1025 static int esp4_rcv_cb(struct sk_buff *skb, int err) 1026 { 1027 return 0; 1028 } 1029 1030 static const struct xfrm_type esp_type = 1031 { 1032 .description = "ESP4", 1033 .owner = THIS_MODULE, 1034 .proto = IPPROTO_ESP, 1035 .flags = XFRM_TYPE_REPLAY_PROT, 1036 .init_state = esp_init_state, 1037 .destructor = esp_destroy, 1038 .get_mtu = esp4_get_mtu, 1039 .input = esp_input, 1040 .output = esp_output, 1041 }; 1042 1043 static struct xfrm4_protocol esp4_protocol = { 1044 .handler = xfrm4_rcv, 1045 .input_handler = xfrm_input, 1046 .cb_handler = esp4_rcv_cb, 1047 .err_handler = esp4_err, 1048 .priority = 0, 1049 }; 1050 1051 static int __init esp4_init(void) 1052 { 1053 if (xfrm_register_type(&esp_type, AF_INET) < 0) { 1054 pr_info("%s: can't add xfrm type\n", __func__); 1055 return -EAGAIN; 1056 } 1057 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { 1058 pr_info("%s: can't add protocol\n", __func__); 1059 xfrm_unregister_type(&esp_type, AF_INET); 1060 return -EAGAIN; 1061 } 1062 return 0; 1063 } 1064 1065 static void __exit esp4_fini(void) 1066 { 1067 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) 1068 pr_info("%s: can't remove protocol\n", __func__); 1069 if (xfrm_unregister_type(&esp_type, AF_INET) < 0) 1070 pr_info("%s: can't remove xfrm type\n", __func__); 1071 } 1072 1073 module_init(esp4_init); 1074 module_exit(esp4_fini); 1075 MODULE_LICENSE("GPL"); 1076 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); 1077