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 /* 37 * Allocate an AEAD request structure with extra space for SG and IV. 38 * 39 * For alignment considerations the IV is placed at the front, followed 40 * by the request and finally the SG list. 41 * 42 * TODO: Use spare space in skb for this where possible. 43 */ 44 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen) 45 { 46 unsigned int len; 47 48 len = extralen; 49 50 len += crypto_aead_ivsize(aead); 51 52 if (len) { 53 len += crypto_aead_alignmask(aead) & 54 ~(crypto_tfm_ctx_alignment() - 1); 55 len = ALIGN(len, crypto_tfm_ctx_alignment()); 56 } 57 58 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); 59 len = ALIGN(len, __alignof__(struct scatterlist)); 60 61 len += sizeof(struct scatterlist) * nfrags; 62 63 return kmalloc(len, GFP_ATOMIC); 64 } 65 66 static inline void *esp_tmp_extra(void *tmp) 67 { 68 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra)); 69 } 70 71 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen) 72 { 73 return crypto_aead_ivsize(aead) ? 74 PTR_ALIGN((u8 *)tmp + extralen, 75 crypto_aead_alignmask(aead) + 1) : tmp + extralen; 76 } 77 78 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) 79 { 80 struct aead_request *req; 81 82 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), 83 crypto_tfm_ctx_alignment()); 84 aead_request_set_tfm(req, aead); 85 return req; 86 } 87 88 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, 89 struct aead_request *req) 90 { 91 return (void *)ALIGN((unsigned long)(req + 1) + 92 crypto_aead_reqsize(aead), 93 __alignof__(struct scatterlist)); 94 } 95 96 static void esp_ssg_unref(struct xfrm_state *x, void *tmp) 97 { 98 struct esp_output_extra *extra = esp_tmp_extra(tmp); 99 struct crypto_aead *aead = x->data; 100 int extralen = 0; 101 u8 *iv; 102 struct aead_request *req; 103 struct scatterlist *sg; 104 105 if (x->props.flags & XFRM_STATE_ESN) 106 extralen += sizeof(*extra); 107 108 extra = esp_tmp_extra(tmp); 109 iv = esp_tmp_iv(aead, tmp, extralen); 110 req = esp_tmp_req(aead, iv); 111 112 /* Unref skb_frag_pages in the src scatterlist if necessary. 113 * Skip the first sg which comes from skb->data. 114 */ 115 if (req->src != req->dst) 116 for (sg = sg_next(req->src); sg; sg = sg_next(sg)) 117 put_page(sg_page(sg)); 118 } 119 120 static void esp_output_done(struct crypto_async_request *base, int err) 121 { 122 struct sk_buff *skb = base->data; 123 struct xfrm_offload *xo = xfrm_offload(skb); 124 void *tmp; 125 struct xfrm_state *x; 126 127 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 128 struct sec_path *sp = skb_sec_path(skb); 129 130 x = sp->xvec[sp->len - 1]; 131 } else { 132 x = skb_dst(skb)->xfrm; 133 } 134 135 tmp = ESP_SKB_CB(skb)->tmp; 136 esp_ssg_unref(x, tmp); 137 kfree(tmp); 138 139 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 140 if (err) { 141 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 142 kfree_skb(skb); 143 return; 144 } 145 146 skb_push(skb, skb->data - skb_mac_header(skb)); 147 secpath_reset(skb); 148 xfrm_dev_resume(skb); 149 } else { 150 xfrm_output_resume(skb, err); 151 } 152 } 153 154 /* Move ESP header back into place. */ 155 static void esp_restore_header(struct sk_buff *skb, unsigned int offset) 156 { 157 struct ip_esp_hdr *esph = (void *)(skb->data + offset); 158 void *tmp = ESP_SKB_CB(skb)->tmp; 159 __be32 *seqhi = esp_tmp_extra(tmp); 160 161 esph->seq_no = esph->spi; 162 esph->spi = *seqhi; 163 } 164 165 static void esp_output_restore_header(struct sk_buff *skb) 166 { 167 void *tmp = ESP_SKB_CB(skb)->tmp; 168 struct esp_output_extra *extra = esp_tmp_extra(tmp); 169 170 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - 171 sizeof(__be32)); 172 } 173 174 static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb, 175 struct xfrm_state *x, 176 struct ip_esp_hdr *esph, 177 struct esp_output_extra *extra) 178 { 179 /* For ESN we move the header forward by 4 bytes to 180 * accomodate the high bits. We will move it back after 181 * encryption. 182 */ 183 if ((x->props.flags & XFRM_STATE_ESN)) { 184 __u32 seqhi; 185 struct xfrm_offload *xo = xfrm_offload(skb); 186 187 if (xo) 188 seqhi = xo->seq.hi; 189 else 190 seqhi = XFRM_SKB_CB(skb)->seq.output.hi; 191 192 extra->esphoff = (unsigned char *)esph - 193 skb_transport_header(skb); 194 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); 195 extra->seqhi = esph->spi; 196 esph->seq_no = htonl(seqhi); 197 } 198 199 esph->spi = x->id.spi; 200 201 return esph; 202 } 203 204 static void esp_output_done_esn(struct crypto_async_request *base, int err) 205 { 206 struct sk_buff *skb = base->data; 207 208 esp_output_restore_header(skb); 209 esp_output_done(base, err); 210 } 211 212 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) 213 { 214 /* Fill padding... */ 215 if (tfclen) { 216 memset(tail, 0, tfclen); 217 tail += tfclen; 218 } 219 do { 220 int i; 221 for (i = 0; i < plen - 2; i++) 222 tail[i] = i + 1; 223 } while (0); 224 tail[plen - 2] = plen - 2; 225 tail[plen - 1] = proto; 226 } 227 228 static int esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 229 { 230 int encap_type; 231 struct udphdr *uh; 232 __be32 *udpdata32; 233 __be16 sport, dport; 234 struct xfrm_encap_tmpl *encap = x->encap; 235 struct ip_esp_hdr *esph = esp->esph; 236 unsigned int len; 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 len = skb->len + esp->tailen - skb_transport_offset(skb); 245 if (len + sizeof(struct iphdr) >= IP_MAX_MTU) 246 return -EMSGSIZE; 247 248 uh = (struct udphdr *)esph; 249 uh->source = sport; 250 uh->dest = dport; 251 uh->len = htons(len); 252 uh->check = 0; 253 254 switch (encap_type) { 255 default: 256 case UDP_ENCAP_ESPINUDP: 257 esph = (struct ip_esp_hdr *)(uh + 1); 258 break; 259 case UDP_ENCAP_ESPINUDP_NON_IKE: 260 udpdata32 = (__be32 *)(uh + 1); 261 udpdata32[0] = udpdata32[1] = 0; 262 esph = (struct ip_esp_hdr *)(udpdata32 + 2); 263 break; 264 } 265 266 *skb_mac_header(skb) = IPPROTO_UDP; 267 esp->esph = esph; 268 269 return 0; 270 } 271 272 int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 273 { 274 u8 *tail; 275 u8 *vaddr; 276 int nfrags; 277 int esph_offset; 278 struct page *page; 279 struct sk_buff *trailer; 280 int tailen = esp->tailen; 281 282 /* this is non-NULL only with UDP Encapsulation */ 283 if (x->encap) { 284 int err = esp_output_udp_encap(x, skb, esp); 285 286 if (err < 0) 287 return err; 288 } 289 290 if (!skb_cloned(skb)) { 291 if (tailen <= skb_tailroom(skb)) { 292 nfrags = 1; 293 trailer = skb; 294 tail = skb_tail_pointer(trailer); 295 296 goto skip_cow; 297 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) 298 && !skb_has_frag_list(skb)) { 299 int allocsize; 300 struct sock *sk = skb->sk; 301 struct page_frag *pfrag = &x->xfrag; 302 303 esp->inplace = false; 304 305 allocsize = ALIGN(tailen, L1_CACHE_BYTES); 306 307 spin_lock_bh(&x->lock); 308 309 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 310 spin_unlock_bh(&x->lock); 311 goto cow; 312 } 313 314 page = pfrag->page; 315 get_page(page); 316 317 vaddr = kmap_atomic(page); 318 319 tail = vaddr + pfrag->offset; 320 321 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 322 323 kunmap_atomic(vaddr); 324 325 nfrags = skb_shinfo(skb)->nr_frags; 326 327 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, 328 tailen); 329 skb_shinfo(skb)->nr_frags = ++nfrags; 330 331 pfrag->offset = pfrag->offset + allocsize; 332 333 spin_unlock_bh(&x->lock); 334 335 nfrags++; 336 337 skb->len += tailen; 338 skb->data_len += tailen; 339 skb->truesize += tailen; 340 if (sk && sk_fullsock(sk)) 341 refcount_add(tailen, &sk->sk_wmem_alloc); 342 343 goto out; 344 } 345 } 346 347 cow: 348 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); 349 350 nfrags = skb_cow_data(skb, tailen, &trailer); 351 if (nfrags < 0) 352 goto out; 353 tail = skb_tail_pointer(trailer); 354 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); 355 356 skip_cow: 357 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 358 pskb_put(skb, trailer, tailen); 359 360 out: 361 return nfrags; 362 } 363 EXPORT_SYMBOL_GPL(esp_output_head); 364 365 int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 366 { 367 u8 *iv; 368 int alen; 369 void *tmp; 370 int ivlen; 371 int assoclen; 372 int extralen; 373 struct page *page; 374 struct ip_esp_hdr *esph; 375 struct crypto_aead *aead; 376 struct aead_request *req; 377 struct scatterlist *sg, *dsg; 378 struct esp_output_extra *extra; 379 int err = -ENOMEM; 380 381 assoclen = sizeof(struct ip_esp_hdr); 382 extralen = 0; 383 384 if (x->props.flags & XFRM_STATE_ESN) { 385 extralen += sizeof(*extra); 386 assoclen += sizeof(__be32); 387 } 388 389 aead = x->data; 390 alen = crypto_aead_authsize(aead); 391 ivlen = crypto_aead_ivsize(aead); 392 393 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); 394 if (!tmp) 395 goto error; 396 397 extra = esp_tmp_extra(tmp); 398 iv = esp_tmp_iv(aead, tmp, extralen); 399 req = esp_tmp_req(aead, iv); 400 sg = esp_req_sg(aead, req); 401 402 if (esp->inplace) 403 dsg = sg; 404 else 405 dsg = &sg[esp->nfrags]; 406 407 esph = esp_output_set_extra(skb, x, esp->esph, extra); 408 esp->esph = esph; 409 410 sg_init_table(sg, esp->nfrags); 411 err = skb_to_sgvec(skb, sg, 412 (unsigned char *)esph - skb->data, 413 assoclen + ivlen + esp->clen + alen); 414 if (unlikely(err < 0)) 415 goto error_free; 416 417 if (!esp->inplace) { 418 int allocsize; 419 struct page_frag *pfrag = &x->xfrag; 420 421 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 422 423 spin_lock_bh(&x->lock); 424 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 425 spin_unlock_bh(&x->lock); 426 goto error_free; 427 } 428 429 skb_shinfo(skb)->nr_frags = 1; 430 431 page = pfrag->page; 432 get_page(page); 433 /* replace page frags in skb with new page */ 434 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 435 pfrag->offset = pfrag->offset + allocsize; 436 spin_unlock_bh(&x->lock); 437 438 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 439 err = skb_to_sgvec(skb, dsg, 440 (unsigned char *)esph - skb->data, 441 assoclen + ivlen + esp->clen + alen); 442 if (unlikely(err < 0)) 443 goto error_free; 444 } 445 446 if ((x->props.flags & XFRM_STATE_ESN)) 447 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 448 else 449 aead_request_set_callback(req, 0, esp_output_done, skb); 450 451 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); 452 aead_request_set_ad(req, assoclen); 453 454 memset(iv, 0, ivlen); 455 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), 456 min(ivlen, 8)); 457 458 ESP_SKB_CB(skb)->tmp = tmp; 459 err = crypto_aead_encrypt(req); 460 461 switch (err) { 462 case -EINPROGRESS: 463 goto error; 464 465 case -ENOSPC: 466 err = NET_XMIT_DROP; 467 break; 468 469 case 0: 470 if ((x->props.flags & XFRM_STATE_ESN)) 471 esp_output_restore_header(skb); 472 } 473 474 if (sg != dsg) 475 esp_ssg_unref(x, tmp); 476 477 error_free: 478 kfree(tmp); 479 error: 480 return err; 481 } 482 EXPORT_SYMBOL_GPL(esp_output_tail); 483 484 static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 485 { 486 int alen; 487 int blksize; 488 struct ip_esp_hdr *esph; 489 struct crypto_aead *aead; 490 struct esp_info esp; 491 492 esp.inplace = true; 493 494 esp.proto = *skb_mac_header(skb); 495 *skb_mac_header(skb) = IPPROTO_ESP; 496 497 /* skb is pure payload to encrypt */ 498 499 aead = x->data; 500 alen = crypto_aead_authsize(aead); 501 502 esp.tfclen = 0; 503 if (x->tfcpad) { 504 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 505 u32 padto; 506 507 padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached)); 508 if (skb->len < padto) 509 esp.tfclen = padto - skb->len; 510 } 511 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 512 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); 513 esp.plen = esp.clen - skb->len - esp.tfclen; 514 esp.tailen = esp.tfclen + esp.plen + alen; 515 516 esp.esph = ip_esp_hdr(skb); 517 518 esp.nfrags = esp_output_head(x, skb, &esp); 519 if (esp.nfrags < 0) 520 return esp.nfrags; 521 522 esph = esp.esph; 523 esph->spi = x->id.spi; 524 525 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 526 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 527 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 528 529 skb_push(skb, -skb_network_offset(skb)); 530 531 return esp_output_tail(x, skb, &esp); 532 } 533 534 static inline int esp_remove_trailer(struct sk_buff *skb) 535 { 536 struct xfrm_state *x = xfrm_input_state(skb); 537 struct xfrm_offload *xo = xfrm_offload(skb); 538 struct crypto_aead *aead = x->data; 539 int alen, hlen, elen; 540 int padlen, trimlen; 541 __wsum csumdiff; 542 u8 nexthdr[2]; 543 int ret; 544 545 alen = crypto_aead_authsize(aead); 546 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 547 elen = skb->len - hlen; 548 549 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { 550 ret = xo->proto; 551 goto out; 552 } 553 554 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2)) 555 BUG(); 556 557 ret = -EINVAL; 558 padlen = nexthdr[0]; 559 if (padlen + 2 + alen >= elen) { 560 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", 561 padlen + 2, elen - alen); 562 goto out; 563 } 564 565 trimlen = alen + padlen + 2; 566 if (skb->ip_summed == CHECKSUM_COMPLETE) { 567 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); 568 skb->csum = csum_block_sub(skb->csum, csumdiff, 569 skb->len - trimlen); 570 } 571 pskb_trim(skb, skb->len - trimlen); 572 573 ret = nexthdr[1]; 574 575 out: 576 return ret; 577 } 578 579 int esp_input_done2(struct sk_buff *skb, int err) 580 { 581 const struct iphdr *iph; 582 struct xfrm_state *x = xfrm_input_state(skb); 583 struct xfrm_offload *xo = xfrm_offload(skb); 584 struct crypto_aead *aead = x->data; 585 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 586 int ihl; 587 588 if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) 589 kfree(ESP_SKB_CB(skb)->tmp); 590 591 if (unlikely(err)) 592 goto out; 593 594 err = esp_remove_trailer(skb); 595 if (unlikely(err < 0)) 596 goto out; 597 598 iph = ip_hdr(skb); 599 ihl = iph->ihl * 4; 600 601 if (x->encap) { 602 struct xfrm_encap_tmpl *encap = x->encap; 603 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); 604 605 /* 606 * 1) if the NAT-T peer's IP or port changed then 607 * advertize the change to the keying daemon. 608 * This is an inbound SA, so just compare 609 * SRC ports. 610 */ 611 if (iph->saddr != x->props.saddr.a4 || 612 uh->source != encap->encap_sport) { 613 xfrm_address_t ipaddr; 614 615 ipaddr.a4 = iph->saddr; 616 km_new_mapping(x, &ipaddr, uh->source); 617 618 /* XXX: perhaps add an extra 619 * policy check here, to see 620 * if we should allow or 621 * reject a packet from a 622 * different source 623 * address/port. 624 */ 625 } 626 627 /* 628 * 2) ignore UDP/TCP checksums in case 629 * of NAT-T in Transport Mode, or 630 * perform other post-processing fixes 631 * as per draft-ietf-ipsec-udp-encaps-06, 632 * section 3.1.2 633 */ 634 if (x->props.mode == XFRM_MODE_TRANSPORT) 635 skb->ip_summed = CHECKSUM_UNNECESSARY; 636 } 637 638 skb_pull_rcsum(skb, hlen); 639 if (x->props.mode == XFRM_MODE_TUNNEL) 640 skb_reset_transport_header(skb); 641 else 642 skb_set_transport_header(skb, -ihl); 643 644 /* RFC4303: Drop dummy packets without any error */ 645 if (err == IPPROTO_NONE) 646 err = -EINVAL; 647 648 out: 649 return err; 650 } 651 EXPORT_SYMBOL_GPL(esp_input_done2); 652 653 static void esp_input_done(struct crypto_async_request *base, int err) 654 { 655 struct sk_buff *skb = base->data; 656 657 xfrm_input_resume(skb, esp_input_done2(skb, err)); 658 } 659 660 static void esp_input_restore_header(struct sk_buff *skb) 661 { 662 esp_restore_header(skb, 0); 663 __skb_pull(skb, 4); 664 } 665 666 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 667 { 668 struct xfrm_state *x = xfrm_input_state(skb); 669 struct ip_esp_hdr *esph; 670 671 /* For ESN we move the header forward by 4 bytes to 672 * accomodate the high bits. We will move it back after 673 * decryption. 674 */ 675 if ((x->props.flags & XFRM_STATE_ESN)) { 676 esph = skb_push(skb, 4); 677 *seqhi = esph->spi; 678 esph->spi = esph->seq_no; 679 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 680 } 681 } 682 683 static void esp_input_done_esn(struct crypto_async_request *base, int err) 684 { 685 struct sk_buff *skb = base->data; 686 687 esp_input_restore_header(skb); 688 esp_input_done(base, err); 689 } 690 691 /* 692 * Note: detecting truncated vs. non-truncated authentication data is very 693 * expensive, so we only support truncated data, which is the recommended 694 * and common case. 695 */ 696 static int esp_input(struct xfrm_state *x, struct sk_buff *skb) 697 { 698 struct crypto_aead *aead = x->data; 699 struct aead_request *req; 700 struct sk_buff *trailer; 701 int ivlen = crypto_aead_ivsize(aead); 702 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen; 703 int nfrags; 704 int assoclen; 705 int seqhilen; 706 __be32 *seqhi; 707 void *tmp; 708 u8 *iv; 709 struct scatterlist *sg; 710 int err = -EINVAL; 711 712 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) 713 goto out; 714 715 if (elen <= 0) 716 goto out; 717 718 assoclen = sizeof(struct ip_esp_hdr); 719 seqhilen = 0; 720 721 if (x->props.flags & XFRM_STATE_ESN) { 722 seqhilen += sizeof(__be32); 723 assoclen += seqhilen; 724 } 725 726 if (!skb_cloned(skb)) { 727 if (!skb_is_nonlinear(skb)) { 728 nfrags = 1; 729 730 goto skip_cow; 731 } else if (!skb_has_frag_list(skb)) { 732 nfrags = skb_shinfo(skb)->nr_frags; 733 nfrags++; 734 735 goto skip_cow; 736 } 737 } 738 739 err = skb_cow_data(skb, 0, &trailer); 740 if (err < 0) 741 goto out; 742 743 nfrags = err; 744 745 skip_cow: 746 err = -ENOMEM; 747 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 748 if (!tmp) 749 goto out; 750 751 ESP_SKB_CB(skb)->tmp = tmp; 752 seqhi = esp_tmp_extra(tmp); 753 iv = esp_tmp_iv(aead, tmp, seqhilen); 754 req = esp_tmp_req(aead, iv); 755 sg = esp_req_sg(aead, req); 756 757 esp_input_set_header(skb, seqhi); 758 759 sg_init_table(sg, nfrags); 760 err = skb_to_sgvec(skb, sg, 0, skb->len); 761 if (unlikely(err < 0)) { 762 kfree(tmp); 763 goto out; 764 } 765 766 skb->ip_summed = CHECKSUM_NONE; 767 768 if ((x->props.flags & XFRM_STATE_ESN)) 769 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 770 else 771 aead_request_set_callback(req, 0, esp_input_done, skb); 772 773 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 774 aead_request_set_ad(req, assoclen); 775 776 err = crypto_aead_decrypt(req); 777 if (err == -EINPROGRESS) 778 goto out; 779 780 if ((x->props.flags & XFRM_STATE_ESN)) 781 esp_input_restore_header(skb); 782 783 err = esp_input_done2(skb, err); 784 785 out: 786 return err; 787 } 788 789 static int esp4_err(struct sk_buff *skb, u32 info) 790 { 791 struct net *net = dev_net(skb->dev); 792 const struct iphdr *iph = (const struct iphdr *)skb->data; 793 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); 794 struct xfrm_state *x; 795 796 switch (icmp_hdr(skb)->type) { 797 case ICMP_DEST_UNREACH: 798 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 799 return 0; 800 case ICMP_REDIRECT: 801 break; 802 default: 803 return 0; 804 } 805 806 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 807 esph->spi, IPPROTO_ESP, AF_INET); 808 if (!x) 809 return 0; 810 811 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) 812 ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP); 813 else 814 ipv4_redirect(skb, net, 0, IPPROTO_ESP); 815 xfrm_state_put(x); 816 817 return 0; 818 } 819 820 static void esp_destroy(struct xfrm_state *x) 821 { 822 struct crypto_aead *aead = x->data; 823 824 if (!aead) 825 return; 826 827 crypto_free_aead(aead); 828 } 829 830 static int esp_init_aead(struct xfrm_state *x) 831 { 832 char aead_name[CRYPTO_MAX_ALG_NAME]; 833 struct crypto_aead *aead; 834 int err; 835 836 err = -ENAMETOOLONG; 837 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 838 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 839 goto error; 840 841 aead = crypto_alloc_aead(aead_name, 0, 0); 842 err = PTR_ERR(aead); 843 if (IS_ERR(aead)) 844 goto error; 845 846 x->data = aead; 847 848 err = crypto_aead_setkey(aead, x->aead->alg_key, 849 (x->aead->alg_key_len + 7) / 8); 850 if (err) 851 goto error; 852 853 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 854 if (err) 855 goto error; 856 857 error: 858 return err; 859 } 860 861 static int esp_init_authenc(struct xfrm_state *x) 862 { 863 struct crypto_aead *aead; 864 struct crypto_authenc_key_param *param; 865 struct rtattr *rta; 866 char *key; 867 char *p; 868 char authenc_name[CRYPTO_MAX_ALG_NAME]; 869 unsigned int keylen; 870 int err; 871 872 err = -EINVAL; 873 if (!x->ealg) 874 goto error; 875 876 err = -ENAMETOOLONG; 877 878 if ((x->props.flags & XFRM_STATE_ESN)) { 879 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 880 "%s%sauthencesn(%s,%s)%s", 881 x->geniv ?: "", x->geniv ? "(" : "", 882 x->aalg ? x->aalg->alg_name : "digest_null", 883 x->ealg->alg_name, 884 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 885 goto error; 886 } else { 887 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 888 "%s%sauthenc(%s,%s)%s", 889 x->geniv ?: "", x->geniv ? "(" : "", 890 x->aalg ? x->aalg->alg_name : "digest_null", 891 x->ealg->alg_name, 892 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 893 goto error; 894 } 895 896 aead = crypto_alloc_aead(authenc_name, 0, 0); 897 err = PTR_ERR(aead); 898 if (IS_ERR(aead)) 899 goto error; 900 901 x->data = aead; 902 903 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 904 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 905 err = -ENOMEM; 906 key = kmalloc(keylen, GFP_KERNEL); 907 if (!key) 908 goto error; 909 910 p = key; 911 rta = (void *)p; 912 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 913 rta->rta_len = RTA_LENGTH(sizeof(*param)); 914 param = RTA_DATA(rta); 915 p += RTA_SPACE(sizeof(*param)); 916 917 if (x->aalg) { 918 struct xfrm_algo_desc *aalg_desc; 919 920 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 921 p += (x->aalg->alg_key_len + 7) / 8; 922 923 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 924 BUG_ON(!aalg_desc); 925 926 err = -EINVAL; 927 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 928 crypto_aead_authsize(aead)) { 929 pr_info("ESP: %s digestsize %u != %hu\n", 930 x->aalg->alg_name, 931 crypto_aead_authsize(aead), 932 aalg_desc->uinfo.auth.icv_fullbits / 8); 933 goto free_key; 934 } 935 936 err = crypto_aead_setauthsize( 937 aead, x->aalg->alg_trunc_len / 8); 938 if (err) 939 goto free_key; 940 } 941 942 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 943 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 944 945 err = crypto_aead_setkey(aead, key, keylen); 946 947 free_key: 948 kfree(key); 949 950 error: 951 return err; 952 } 953 954 static int esp_init_state(struct xfrm_state *x) 955 { 956 struct crypto_aead *aead; 957 u32 align; 958 int err; 959 960 x->data = NULL; 961 962 if (x->aead) 963 err = esp_init_aead(x); 964 else 965 err = esp_init_authenc(x); 966 967 if (err) 968 goto error; 969 970 aead = x->data; 971 972 x->props.header_len = sizeof(struct ip_esp_hdr) + 973 crypto_aead_ivsize(aead); 974 if (x->props.mode == XFRM_MODE_TUNNEL) 975 x->props.header_len += sizeof(struct iphdr); 976 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) 977 x->props.header_len += IPV4_BEET_PHMAXLEN; 978 if (x->encap) { 979 struct xfrm_encap_tmpl *encap = x->encap; 980 981 switch (encap->encap_type) { 982 default: 983 err = -EINVAL; 984 goto error; 985 case UDP_ENCAP_ESPINUDP: 986 x->props.header_len += sizeof(struct udphdr); 987 break; 988 case UDP_ENCAP_ESPINUDP_NON_IKE: 989 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 990 break; 991 } 992 } 993 994 align = ALIGN(crypto_aead_blocksize(aead), 4); 995 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 996 997 error: 998 return err; 999 } 1000 1001 static int esp4_rcv_cb(struct sk_buff *skb, int err) 1002 { 1003 return 0; 1004 } 1005 1006 static const struct xfrm_type esp_type = 1007 { 1008 .description = "ESP4", 1009 .owner = THIS_MODULE, 1010 .proto = IPPROTO_ESP, 1011 .flags = XFRM_TYPE_REPLAY_PROT, 1012 .init_state = esp_init_state, 1013 .destructor = esp_destroy, 1014 .input = esp_input, 1015 .output = esp_output, 1016 }; 1017 1018 static struct xfrm4_protocol esp4_protocol = { 1019 .handler = xfrm4_rcv, 1020 .input_handler = xfrm_input, 1021 .cb_handler = esp4_rcv_cb, 1022 .err_handler = esp4_err, 1023 .priority = 0, 1024 }; 1025 1026 static int __init esp4_init(void) 1027 { 1028 if (xfrm_register_type(&esp_type, AF_INET) < 0) { 1029 pr_info("%s: can't add xfrm type\n", __func__); 1030 return -EAGAIN; 1031 } 1032 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { 1033 pr_info("%s: can't add protocol\n", __func__); 1034 xfrm_unregister_type(&esp_type, AF_INET); 1035 return -EAGAIN; 1036 } 1037 return 0; 1038 } 1039 1040 static void __exit esp4_fini(void) 1041 { 1042 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) 1043 pr_info("%s: can't remove protocol\n", __func__); 1044 xfrm_unregister_type(&esp_type, AF_INET); 1045 } 1046 1047 module_init(esp4_init); 1048 module_exit(esp4_fini); 1049 MODULE_LICENSE("GPL"); 1050 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); 1051