1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Copyright (C)2002 USAGI/WIDE Project 4 * 5 * Authors 6 * 7 * Mitsuru KANDA @USAGI : IPv6 Support 8 * Kazunori MIYAZAWA @USAGI : 9 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 10 * 11 * This file is derived from net/ipv4/esp.c 12 */ 13 14#define pr_fmt(fmt) "IPv6: " fmt 15 16#include <crypto/aead.h> 17#include <crypto/authenc.h> 18#include <linux/err.h> 19#include <linux/module.h> 20#include <net/ip.h> 21#include <net/xfrm.h> 22#include <net/esp.h> 23#include <linux/scatterlist.h> 24#include <linux/kernel.h> 25#include <linux/pfkeyv2.h> 26#include <linux/random.h> 27#include <linux/slab.h> 28#include <linux/spinlock.h> 29#include <net/ip6_checksum.h> 30#include <net/ip6_route.h> 31#include <net/icmp.h> 32#include <net/ipv6.h> 33#include <net/protocol.h> 34#include <net/udp.h> 35#include <linux/icmpv6.h> 36#include <net/tcp.h> 37#include <net/espintcp.h> 38#include <net/inet6_hashtables.h> 39 40#include <linux/highmem.h> 41 42struct esp_skb_cb { 43 struct xfrm_skb_cb xfrm; 44 void *tmp; 45}; 46 47struct esp_output_extra { 48 __be32 seqhi; 49 u32 esphoff; 50}; 51 52#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) 53 54/* 55 * Allocate an AEAD request structure with extra space for SG and IV. 56 * 57 * For alignment considerations the upper 32 bits of the sequence number are 58 * placed at the front, if present. Followed by the IV, the request and finally 59 * the SG list. 60 * 61 * TODO: Use spare space in skb for this where possible. 62 */ 63static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen) 64{ 65 unsigned int len; 66 67 len = seqihlen; 68 69 len += crypto_aead_ivsize(aead); 70 71 if (len) { 72 len += crypto_aead_alignmask(aead) & 73 ~(crypto_tfm_ctx_alignment() - 1); 74 len = ALIGN(len, crypto_tfm_ctx_alignment()); 75 } 76 77 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); 78 len = ALIGN(len, __alignof__(struct scatterlist)); 79 80 len += sizeof(struct scatterlist) * nfrags; 81 82 return kmalloc(len, GFP_ATOMIC); 83} 84 85static inline void *esp_tmp_extra(void *tmp) 86{ 87 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra)); 88} 89 90static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen) 91{ 92 return crypto_aead_ivsize(aead) ? 93 PTR_ALIGN((u8 *)tmp + seqhilen, 94 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen; 95} 96 97static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) 98{ 99 struct aead_request *req; 100 101 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), 102 crypto_tfm_ctx_alignment()); 103 aead_request_set_tfm(req, aead); 104 return req; 105} 106 107static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, 108 struct aead_request *req) 109{ 110 return (void *)ALIGN((unsigned long)(req + 1) + 111 crypto_aead_reqsize(aead), 112 __alignof__(struct scatterlist)); 113} 114 115static void esp_ssg_unref(struct xfrm_state *x, void *tmp) 116{ 117 struct esp_output_extra *extra = esp_tmp_extra(tmp); 118 struct crypto_aead *aead = x->data; 119 int extralen = 0; 120 u8 *iv; 121 struct aead_request *req; 122 struct scatterlist *sg; 123 124 if (x->props.flags & XFRM_STATE_ESN) 125 extralen += sizeof(*extra); 126 127 iv = esp_tmp_iv(aead, tmp, extralen); 128 req = esp_tmp_req(aead, iv); 129 130 /* Unref skb_frag_pages in the src scatterlist if necessary. 131 * Skip the first sg which comes from skb->data. 132 */ 133 if (req->src != req->dst) 134 for (sg = sg_next(req->src); sg; sg = sg_next(sg)) 135 put_page(sg_page(sg)); 136} 137 138#ifdef CONFIG_INET6_ESPINTCP 139struct esp_tcp_sk { 140 struct sock *sk; 141 struct rcu_head rcu; 142}; 143 144static void esp_free_tcp_sk(struct rcu_head *head) 145{ 146 struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu); 147 148 sock_put(esk->sk); 149 kfree(esk); 150} 151 152static struct sock *esp6_find_tcp_sk(struct xfrm_state *x) 153{ 154 struct xfrm_encap_tmpl *encap = x->encap; 155 struct esp_tcp_sk *esk; 156 __be16 sport, dport; 157 struct sock *nsk; 158 struct sock *sk; 159 160 sk = rcu_dereference(x->encap_sk); 161 if (sk && sk->sk_state == TCP_ESTABLISHED) 162 return sk; 163 164 spin_lock_bh(&x->lock); 165 sport = encap->encap_sport; 166 dport = encap->encap_dport; 167 nsk = rcu_dereference_protected(x->encap_sk, 168 lockdep_is_held(&x->lock)); 169 if (sk && sk == nsk) { 170 esk = kmalloc(sizeof(*esk), GFP_ATOMIC); 171 if (!esk) { 172 spin_unlock_bh(&x->lock); 173 return ERR_PTR(-ENOMEM); 174 } 175 RCU_INIT_POINTER(x->encap_sk, NULL); 176 esk->sk = sk; 177 call_rcu(&esk->rcu, esp_free_tcp_sk); 178 } 179 spin_unlock_bh(&x->lock); 180 181 sk = __inet6_lookup_established(xs_net(x), &tcp_hashinfo, &x->id.daddr.in6, 182 dport, &x->props.saddr.in6, ntohs(sport), 0, 0); 183 if (!sk) 184 return ERR_PTR(-ENOENT); 185 186 if (!tcp_is_ulp_esp(sk)) { 187 sock_put(sk); 188 return ERR_PTR(-EINVAL); 189 } 190 191 spin_lock_bh(&x->lock); 192 nsk = rcu_dereference_protected(x->encap_sk, 193 lockdep_is_held(&x->lock)); 194 if (encap->encap_sport != sport || 195 encap->encap_dport != dport) { 196 sock_put(sk); 197 sk = nsk ?: ERR_PTR(-EREMCHG); 198 } else if (sk == nsk) { 199 sock_put(sk); 200 } else { 201 rcu_assign_pointer(x->encap_sk, sk); 202 } 203 spin_unlock_bh(&x->lock); 204 205 return sk; 206} 207 208static int esp_output_tcp_finish(struct xfrm_state *x, struct sk_buff *skb) 209{ 210 struct sock *sk; 211 int err; 212 213 rcu_read_lock(); 214 215 sk = esp6_find_tcp_sk(x); 216 err = PTR_ERR_OR_ZERO(sk); 217 if (err) 218 goto out; 219 220 bh_lock_sock(sk); 221 if (sock_owned_by_user(sk)) 222 err = espintcp_queue_out(sk, skb); 223 else 224 err = espintcp_push_skb(sk, skb); 225 bh_unlock_sock(sk); 226 227out: 228 rcu_read_unlock(); 229 return err; 230} 231 232static int esp_output_tcp_encap_cb(struct net *net, struct sock *sk, 233 struct sk_buff *skb) 234{ 235 struct dst_entry *dst = skb_dst(skb); 236 struct xfrm_state *x = dst->xfrm; 237 238 return esp_output_tcp_finish(x, skb); 239} 240 241static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb) 242{ 243 int err; 244 245 local_bh_disable(); 246 err = xfrm_trans_queue_net(xs_net(x), skb, esp_output_tcp_encap_cb); 247 local_bh_enable(); 248 249 /* EINPROGRESS just happens to do the right thing. It 250 * actually means that the skb has been consumed and 251 * isn't coming back. 252 */ 253 return err ?: -EINPROGRESS; 254} 255#else 256static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb) 257{ 258 kfree_skb(skb); 259 260 return -EOPNOTSUPP; 261} 262#endif 263 264static void esp_output_encap_csum(struct sk_buff *skb) 265{ 266 /* UDP encap with IPv6 requires a valid checksum */ 267 if (*skb_mac_header(skb) == IPPROTO_UDP) { 268 struct udphdr *uh = udp_hdr(skb); 269 struct ipv6hdr *ip6h = ipv6_hdr(skb); 270 int len = ntohs(uh->len); 271 unsigned int offset = skb_transport_offset(skb); 272 __wsum csum = skb_checksum(skb, offset, skb->len - offset, 0); 273 274 uh->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 275 len, IPPROTO_UDP, csum); 276 if (uh->check == 0) 277 uh->check = CSUM_MANGLED_0; 278 } 279} 280 281static void esp_output_done(struct crypto_async_request *base, int err) 282{ 283 struct sk_buff *skb = base->data; 284 struct xfrm_offload *xo = xfrm_offload(skb); 285 void *tmp; 286 struct xfrm_state *x; 287 288 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 289 struct sec_path *sp = skb_sec_path(skb); 290 291 x = sp->xvec[sp->len - 1]; 292 } else { 293 x = skb_dst(skb)->xfrm; 294 } 295 296 tmp = ESP_SKB_CB(skb)->tmp; 297 esp_ssg_unref(x, tmp); 298 kfree(tmp); 299 300 esp_output_encap_csum(skb); 301 302 if (xo && (xo->flags & XFRM_DEV_RESUME)) { 303 if (err) { 304 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 305 kfree_skb(skb); 306 return; 307 } 308 309 skb_push(skb, skb->data - skb_mac_header(skb)); 310 secpath_reset(skb); 311 xfrm_dev_resume(skb); 312 } else { 313 if (!err && 314 x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP) 315 esp_output_tail_tcp(x, skb); 316 else 317 xfrm_output_resume(skb->sk, skb, err); 318 } 319} 320 321/* Move ESP header back into place. */ 322static void esp_restore_header(struct sk_buff *skb, unsigned int offset) 323{ 324 struct ip_esp_hdr *esph = (void *)(skb->data + offset); 325 void *tmp = ESP_SKB_CB(skb)->tmp; 326 __be32 *seqhi = esp_tmp_extra(tmp); 327 328 esph->seq_no = esph->spi; 329 esph->spi = *seqhi; 330} 331 332static void esp_output_restore_header(struct sk_buff *skb) 333{ 334 void *tmp = ESP_SKB_CB(skb)->tmp; 335 struct esp_output_extra *extra = esp_tmp_extra(tmp); 336 337 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - 338 sizeof(__be32)); 339} 340 341static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb, 342 struct xfrm_state *x, 343 struct ip_esp_hdr *esph, 344 struct esp_output_extra *extra) 345{ 346 /* For ESN we move the header forward by 4 bytes to 347 * accomodate the high bits. We will move it back after 348 * encryption. 349 */ 350 if ((x->props.flags & XFRM_STATE_ESN)) { 351 __u32 seqhi; 352 struct xfrm_offload *xo = xfrm_offload(skb); 353 354 if (xo) 355 seqhi = xo->seq.hi; 356 else 357 seqhi = XFRM_SKB_CB(skb)->seq.output.hi; 358 359 extra->esphoff = (unsigned char *)esph - 360 skb_transport_header(skb); 361 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); 362 extra->seqhi = esph->spi; 363 esph->seq_no = htonl(seqhi); 364 } 365 366 esph->spi = x->id.spi; 367 368 return esph; 369} 370 371static void esp_output_done_esn(struct crypto_async_request *base, int err) 372{ 373 struct sk_buff *skb = base->data; 374 375 esp_output_restore_header(skb); 376 esp_output_done(base, err); 377} 378 379static struct ip_esp_hdr *esp6_output_udp_encap(struct sk_buff *skb, 380 int encap_type, 381 struct esp_info *esp, 382 __be16 sport, 383 __be16 dport) 384{ 385 struct udphdr *uh; 386 __be32 *udpdata32; 387 unsigned int len; 388 389 len = skb->len + esp->tailen - skb_transport_offset(skb); 390 if (len > U16_MAX) 391 return ERR_PTR(-EMSGSIZE); 392 393 uh = (struct udphdr *)esp->esph; 394 uh->source = sport; 395 uh->dest = dport; 396 uh->len = htons(len); 397 uh->check = 0; 398 399 *skb_mac_header(skb) = IPPROTO_UDP; 400 401 if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) { 402 udpdata32 = (__be32 *)(uh + 1); 403 udpdata32[0] = udpdata32[1] = 0; 404 return (struct ip_esp_hdr *)(udpdata32 + 2); 405 } 406 407 return (struct ip_esp_hdr *)(uh + 1); 408} 409 410#ifdef CONFIG_INET6_ESPINTCP 411static struct ip_esp_hdr *esp6_output_tcp_encap(struct xfrm_state *x, 412 struct sk_buff *skb, 413 struct esp_info *esp) 414{ 415 __be16 *lenp = (void *)esp->esph; 416 struct ip_esp_hdr *esph; 417 unsigned int len; 418 struct sock *sk; 419 420 len = skb->len + esp->tailen - skb_transport_offset(skb); 421 if (len > IP_MAX_MTU) 422 return ERR_PTR(-EMSGSIZE); 423 424 rcu_read_lock(); 425 sk = esp6_find_tcp_sk(x); 426 rcu_read_unlock(); 427 428 if (IS_ERR(sk)) 429 return ERR_CAST(sk); 430 431 *lenp = htons(len); 432 esph = (struct ip_esp_hdr *)(lenp + 1); 433 434 return esph; 435} 436#else 437static struct ip_esp_hdr *esp6_output_tcp_encap(struct xfrm_state *x, 438 struct sk_buff *skb, 439 struct esp_info *esp) 440{ 441 return ERR_PTR(-EOPNOTSUPP); 442} 443#endif 444 445static int esp6_output_encap(struct xfrm_state *x, struct sk_buff *skb, 446 struct esp_info *esp) 447{ 448 struct xfrm_encap_tmpl *encap = x->encap; 449 struct ip_esp_hdr *esph; 450 __be16 sport, dport; 451 int encap_type; 452 453 spin_lock_bh(&x->lock); 454 sport = encap->encap_sport; 455 dport = encap->encap_dport; 456 encap_type = encap->encap_type; 457 spin_unlock_bh(&x->lock); 458 459 switch (encap_type) { 460 default: 461 case UDP_ENCAP_ESPINUDP: 462 case UDP_ENCAP_ESPINUDP_NON_IKE: 463 esph = esp6_output_udp_encap(skb, encap_type, esp, sport, dport); 464 break; 465 case TCP_ENCAP_ESPINTCP: 466 esph = esp6_output_tcp_encap(x, skb, esp); 467 break; 468 } 469 470 if (IS_ERR(esph)) 471 return PTR_ERR(esph); 472 473 esp->esph = esph; 474 475 return 0; 476} 477 478int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 479{ 480 u8 *tail; 481 int nfrags; 482 int esph_offset; 483 struct page *page; 484 struct sk_buff *trailer; 485 int tailen = esp->tailen; 486 487 if (x->encap) { 488 int err = esp6_output_encap(x, skb, esp); 489 490 if (err < 0) 491 return err; 492 } 493 494 if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE || 495 ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE) 496 goto cow; 497 498 if (!skb_cloned(skb)) { 499 if (tailen <= skb_tailroom(skb)) { 500 nfrags = 1; 501 trailer = skb; 502 tail = skb_tail_pointer(trailer); 503 504 goto skip_cow; 505 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) 506 && !skb_has_frag_list(skb)) { 507 int allocsize; 508 struct sock *sk = skb->sk; 509 struct page_frag *pfrag = &x->xfrag; 510 511 esp->inplace = false; 512 513 allocsize = ALIGN(tailen, L1_CACHE_BYTES); 514 515 spin_lock_bh(&x->lock); 516 517 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 518 spin_unlock_bh(&x->lock); 519 goto cow; 520 } 521 522 page = pfrag->page; 523 get_page(page); 524 525 tail = page_address(page) + pfrag->offset; 526 527 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 528 529 nfrags = skb_shinfo(skb)->nr_frags; 530 531 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, 532 tailen); 533 skb_shinfo(skb)->nr_frags = ++nfrags; 534 535 pfrag->offset = pfrag->offset + allocsize; 536 537 spin_unlock_bh(&x->lock); 538 539 nfrags++; 540 541 skb->len += tailen; 542 skb->data_len += tailen; 543 skb->truesize += tailen; 544 if (sk && sk_fullsock(sk)) 545 refcount_add(tailen, &sk->sk_wmem_alloc); 546 547 goto out; 548 } 549 } 550 551cow: 552 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); 553 554 nfrags = skb_cow_data(skb, tailen, &trailer); 555 if (nfrags < 0) 556 goto out; 557 tail = skb_tail_pointer(trailer); 558 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); 559 560skip_cow: 561 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); 562 pskb_put(skb, trailer, tailen); 563 564out: 565 return nfrags; 566} 567EXPORT_SYMBOL_GPL(esp6_output_head); 568 569int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) 570{ 571 u8 *iv; 572 int alen; 573 void *tmp; 574 int ivlen; 575 int assoclen; 576 int extralen; 577 struct page *page; 578 struct ip_esp_hdr *esph; 579 struct aead_request *req; 580 struct crypto_aead *aead; 581 struct scatterlist *sg, *dsg; 582 struct esp_output_extra *extra; 583 int err = -ENOMEM; 584 585 assoclen = sizeof(struct ip_esp_hdr); 586 extralen = 0; 587 588 if (x->props.flags & XFRM_STATE_ESN) { 589 extralen += sizeof(*extra); 590 assoclen += sizeof(__be32); 591 } 592 593 aead = x->data; 594 alen = crypto_aead_authsize(aead); 595 ivlen = crypto_aead_ivsize(aead); 596 597 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); 598 if (!tmp) 599 goto error; 600 601 extra = esp_tmp_extra(tmp); 602 iv = esp_tmp_iv(aead, tmp, extralen); 603 req = esp_tmp_req(aead, iv); 604 sg = esp_req_sg(aead, req); 605 606 if (esp->inplace) 607 dsg = sg; 608 else 609 dsg = &sg[esp->nfrags]; 610 611 esph = esp_output_set_esn(skb, x, esp->esph, extra); 612 esp->esph = esph; 613 614 sg_init_table(sg, esp->nfrags); 615 err = skb_to_sgvec(skb, sg, 616 (unsigned char *)esph - skb->data, 617 assoclen + ivlen + esp->clen + alen); 618 if (unlikely(err < 0)) 619 goto error_free; 620 621 if (!esp->inplace) { 622 int allocsize; 623 struct page_frag *pfrag = &x->xfrag; 624 625 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); 626 627 spin_lock_bh(&x->lock); 628 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { 629 spin_unlock_bh(&x->lock); 630 goto error_free; 631 } 632 633 skb_shinfo(skb)->nr_frags = 1; 634 635 page = pfrag->page; 636 get_page(page); 637 /* replace page frags in skb with new page */ 638 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); 639 pfrag->offset = pfrag->offset + allocsize; 640 spin_unlock_bh(&x->lock); 641 642 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); 643 err = skb_to_sgvec(skb, dsg, 644 (unsigned char *)esph - skb->data, 645 assoclen + ivlen + esp->clen + alen); 646 if (unlikely(err < 0)) 647 goto error_free; 648 } 649 650 if ((x->props.flags & XFRM_STATE_ESN)) 651 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 652 else 653 aead_request_set_callback(req, 0, esp_output_done, skb); 654 655 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); 656 aead_request_set_ad(req, assoclen); 657 658 memset(iv, 0, ivlen); 659 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), 660 min(ivlen, 8)); 661 662 ESP_SKB_CB(skb)->tmp = tmp; 663 err = crypto_aead_encrypt(req); 664 665 switch (err) { 666 case -EINPROGRESS: 667 goto error; 668 669 case -ENOSPC: 670 err = NET_XMIT_DROP; 671 break; 672 673 case 0: 674 if ((x->props.flags & XFRM_STATE_ESN)) 675 esp_output_restore_header(skb); 676 esp_output_encap_csum(skb); 677 } 678 679 if (sg != dsg) 680 esp_ssg_unref(x, tmp); 681 682 if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP) 683 err = esp_output_tail_tcp(x, skb); 684 685error_free: 686 kfree(tmp); 687error: 688 return err; 689} 690EXPORT_SYMBOL_GPL(esp6_output_tail); 691 692static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) 693{ 694 int alen; 695 int blksize; 696 struct ip_esp_hdr *esph; 697 struct crypto_aead *aead; 698 struct esp_info esp; 699 700 esp.inplace = true; 701 702 esp.proto = *skb_mac_header(skb); 703 *skb_mac_header(skb) = IPPROTO_ESP; 704 705 /* skb is pure payload to encrypt */ 706 707 aead = x->data; 708 alen = crypto_aead_authsize(aead); 709 710 esp.tfclen = 0; 711 if (x->tfcpad) { 712 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 713 u32 padto; 714 715 padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached)); 716 if (skb->len < padto) 717 esp.tfclen = padto - skb->len; 718 } 719 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 720 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); 721 esp.plen = esp.clen - skb->len - esp.tfclen; 722 esp.tailen = esp.tfclen + esp.plen + alen; 723 724 esp.esph = ip_esp_hdr(skb); 725 726 esp.nfrags = esp6_output_head(x, skb, &esp); 727 if (esp.nfrags < 0) 728 return esp.nfrags; 729 730 esph = esp.esph; 731 esph->spi = x->id.spi; 732 733 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 734 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 735 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 736 737 skb_push(skb, -skb_network_offset(skb)); 738 739 return esp6_output_tail(x, skb, &esp); 740} 741 742static inline int esp_remove_trailer(struct sk_buff *skb) 743{ 744 struct xfrm_state *x = xfrm_input_state(skb); 745 struct xfrm_offload *xo = xfrm_offload(skb); 746 struct crypto_aead *aead = x->data; 747 int alen, hlen, elen; 748 int padlen, trimlen; 749 __wsum csumdiff; 750 u8 nexthdr[2]; 751 int ret; 752 753 alen = crypto_aead_authsize(aead); 754 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 755 elen = skb->len - hlen; 756 757 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { 758 ret = xo->proto; 759 goto out; 760 } 761 762 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2); 763 BUG_ON(ret); 764 765 ret = -EINVAL; 766 padlen = nexthdr[0]; 767 if (padlen + 2 + alen >= elen) { 768 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", 769 padlen + 2, elen - alen); 770 goto out; 771 } 772 773 trimlen = alen + padlen + 2; 774 if (skb->ip_summed == CHECKSUM_COMPLETE) { 775 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); 776 skb->csum = csum_block_sub(skb->csum, csumdiff, 777 skb->len - trimlen); 778 } 779 ret = pskb_trim(skb, skb->len - trimlen); 780 if (unlikely(ret)) 781 return ret; 782 783 ret = nexthdr[1]; 784 785out: 786 return ret; 787} 788 789int esp6_input_done2(struct sk_buff *skb, int err) 790{ 791 struct xfrm_state *x = xfrm_input_state(skb); 792 struct xfrm_offload *xo = xfrm_offload(skb); 793 struct crypto_aead *aead = x->data; 794 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 795 int hdr_len = skb_network_header_len(skb); 796 797 if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) 798 kfree(ESP_SKB_CB(skb)->tmp); 799 800 if (unlikely(err)) 801 goto out; 802 803 err = esp_remove_trailer(skb); 804 if (unlikely(err < 0)) 805 goto out; 806 807 if (x->encap) { 808 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 809 int offset = skb_network_offset(skb) + sizeof(*ip6h); 810 struct xfrm_encap_tmpl *encap = x->encap; 811 u8 nexthdr = ip6h->nexthdr; 812 __be16 frag_off, source; 813 struct udphdr *uh; 814 struct tcphdr *th; 815 816 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); 817 if (offset == -1) { 818 err = -EINVAL; 819 goto out; 820 } 821 822 uh = (void *)(skb->data + offset); 823 th = (void *)(skb->data + offset); 824 hdr_len += offset; 825 826 switch (x->encap->encap_type) { 827 case TCP_ENCAP_ESPINTCP: 828 source = th->source; 829 break; 830 case UDP_ENCAP_ESPINUDP: 831 case UDP_ENCAP_ESPINUDP_NON_IKE: 832 source = uh->source; 833 break; 834 default: 835 WARN_ON_ONCE(1); 836 err = -EINVAL; 837 goto out; 838 } 839 840 /* 841 * 1) if the NAT-T peer's IP or port changed then 842 * advertize the change to the keying daemon. 843 * This is an inbound SA, so just compare 844 * SRC ports. 845 */ 846 if (!ipv6_addr_equal(&ip6h->saddr, &x->props.saddr.in6) || 847 source != encap->encap_sport) { 848 xfrm_address_t ipaddr; 849 850 memcpy(&ipaddr.a6, &ip6h->saddr.s6_addr, sizeof(ipaddr.a6)); 851 km_new_mapping(x, &ipaddr, source); 852 853 /* XXX: perhaps add an extra 854 * policy check here, to see 855 * if we should allow or 856 * reject a packet from a 857 * different source 858 * address/port. 859 */ 860 } 861 862 /* 863 * 2) ignore UDP/TCP checksums in case 864 * of NAT-T in Transport Mode, or 865 * perform other post-processing fixes 866 * as per draft-ietf-ipsec-udp-encaps-06, 867 * section 3.1.2 868 */ 869 if (x->props.mode == XFRM_MODE_TRANSPORT) 870 skb->ip_summed = CHECKSUM_UNNECESSARY; 871 } 872 873 skb_postpull_rcsum(skb, skb_network_header(skb), 874 skb_network_header_len(skb)); 875 skb_pull_rcsum(skb, hlen); 876 if (x->props.mode == XFRM_MODE_TUNNEL) 877 skb_reset_transport_header(skb); 878 else 879 skb_set_transport_header(skb, -hdr_len); 880 881 /* RFC4303: Drop dummy packets without any error */ 882 if (err == IPPROTO_NONE) 883 err = -EINVAL; 884 885out: 886 return err; 887} 888EXPORT_SYMBOL_GPL(esp6_input_done2); 889 890static void esp_input_done(struct crypto_async_request *base, int err) 891{ 892 struct sk_buff *skb = base->data; 893 894 xfrm_input_resume(skb, esp6_input_done2(skb, err)); 895} 896 897static void esp_input_restore_header(struct sk_buff *skb) 898{ 899 esp_restore_header(skb, 0); 900 __skb_pull(skb, 4); 901} 902 903static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 904{ 905 struct xfrm_state *x = xfrm_input_state(skb); 906 907 /* For ESN we move the header forward by 4 bytes to 908 * accomodate the high bits. We will move it back after 909 * decryption. 910 */ 911 if ((x->props.flags & XFRM_STATE_ESN)) { 912 struct ip_esp_hdr *esph = skb_push(skb, 4); 913 914 *seqhi = esph->spi; 915 esph->spi = esph->seq_no; 916 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 917 } 918} 919 920static void esp_input_done_esn(struct crypto_async_request *base, int err) 921{ 922 struct sk_buff *skb = base->data; 923 924 esp_input_restore_header(skb); 925 esp_input_done(base, err); 926} 927 928static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) 929{ 930 struct crypto_aead *aead = x->data; 931 struct aead_request *req; 932 struct sk_buff *trailer; 933 int ivlen = crypto_aead_ivsize(aead); 934 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen; 935 int nfrags; 936 int assoclen; 937 int seqhilen; 938 int ret = 0; 939 void *tmp; 940 __be32 *seqhi; 941 u8 *iv; 942 struct scatterlist *sg; 943 944 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) { 945 ret = -EINVAL; 946 goto out; 947 } 948 949 if (elen <= 0) { 950 ret = -EINVAL; 951 goto out; 952 } 953 954 assoclen = sizeof(struct ip_esp_hdr); 955 seqhilen = 0; 956 957 if (x->props.flags & XFRM_STATE_ESN) { 958 seqhilen += sizeof(__be32); 959 assoclen += seqhilen; 960 } 961 962 if (!skb_cloned(skb)) { 963 if (!skb_is_nonlinear(skb)) { 964 nfrags = 1; 965 966 goto skip_cow; 967 } else if (!skb_has_frag_list(skb)) { 968 nfrags = skb_shinfo(skb)->nr_frags; 969 nfrags++; 970 971 goto skip_cow; 972 } 973 } 974 975 nfrags = skb_cow_data(skb, 0, &trailer); 976 if (nfrags < 0) { 977 ret = -EINVAL; 978 goto out; 979 } 980 981skip_cow: 982 ret = -ENOMEM; 983 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 984 if (!tmp) 985 goto out; 986 987 ESP_SKB_CB(skb)->tmp = tmp; 988 seqhi = esp_tmp_extra(tmp); 989 iv = esp_tmp_iv(aead, tmp, seqhilen); 990 req = esp_tmp_req(aead, iv); 991 sg = esp_req_sg(aead, req); 992 993 esp_input_set_header(skb, seqhi); 994 995 sg_init_table(sg, nfrags); 996 ret = skb_to_sgvec(skb, sg, 0, skb->len); 997 if (unlikely(ret < 0)) { 998 kfree(tmp); 999 goto out; 1000 } 1001 1002 skb->ip_summed = CHECKSUM_NONE; 1003 1004 if ((x->props.flags & XFRM_STATE_ESN)) 1005 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 1006 else 1007 aead_request_set_callback(req, 0, esp_input_done, skb); 1008 1009 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 1010 aead_request_set_ad(req, assoclen); 1011 1012 ret = crypto_aead_decrypt(req); 1013 if (ret == -EINPROGRESS) 1014 goto out; 1015 1016 if ((x->props.flags & XFRM_STATE_ESN)) 1017 esp_input_restore_header(skb); 1018 1019 ret = esp6_input_done2(skb, ret); 1020 1021out: 1022 return ret; 1023} 1024 1025static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 1026 u8 type, u8 code, int offset, __be32 info) 1027{ 1028 struct net *net = dev_net(skb->dev); 1029 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 1030 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset); 1031 struct xfrm_state *x; 1032 1033 if (type != ICMPV6_PKT_TOOBIG && 1034 type != NDISC_REDIRECT) 1035 return 0; 1036 1037 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 1038 esph->spi, IPPROTO_ESP, AF_INET6); 1039 if (!x) 1040 return 0; 1041 1042 if (type == NDISC_REDIRECT) 1043 ip6_redirect(skb, net, skb->dev->ifindex, 0, 1044 sock_net_uid(net, NULL)); 1045 else 1046 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 1047 xfrm_state_put(x); 1048 1049 return 0; 1050} 1051 1052static void esp6_destroy(struct xfrm_state *x) 1053{ 1054 struct crypto_aead *aead = x->data; 1055 1056 if (!aead) 1057 return; 1058 1059 crypto_free_aead(aead); 1060} 1061 1062static int esp_init_aead(struct xfrm_state *x) 1063{ 1064 char aead_name[CRYPTO_MAX_ALG_NAME]; 1065 struct crypto_aead *aead; 1066 int err; 1067 1068 err = -ENAMETOOLONG; 1069 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 1070 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 1071 goto error; 1072 1073 aead = crypto_alloc_aead(aead_name, 0, 0); 1074 err = PTR_ERR(aead); 1075 if (IS_ERR(aead)) 1076 goto error; 1077 1078 x->data = aead; 1079 1080 err = crypto_aead_setkey(aead, x->aead->alg_key, 1081 (x->aead->alg_key_len + 7) / 8); 1082 if (err) 1083 goto error; 1084 1085 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 1086 if (err) 1087 goto error; 1088 1089error: 1090 return err; 1091} 1092 1093static int esp_init_authenc(struct xfrm_state *x) 1094{ 1095 struct crypto_aead *aead; 1096 struct crypto_authenc_key_param *param; 1097 struct rtattr *rta; 1098 char *key; 1099 char *p; 1100 char authenc_name[CRYPTO_MAX_ALG_NAME]; 1101 unsigned int keylen; 1102 int err; 1103 1104 err = -EINVAL; 1105 if (!x->ealg) 1106 goto error; 1107 1108 err = -ENAMETOOLONG; 1109 1110 if ((x->props.flags & XFRM_STATE_ESN)) { 1111 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 1112 "%s%sauthencesn(%s,%s)%s", 1113 x->geniv ?: "", x->geniv ? "(" : "", 1114 x->aalg ? x->aalg->alg_name : "digest_null", 1115 x->ealg->alg_name, 1116 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 1117 goto error; 1118 } else { 1119 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 1120 "%s%sauthenc(%s,%s)%s", 1121 x->geniv ?: "", x->geniv ? "(" : "", 1122 x->aalg ? x->aalg->alg_name : "digest_null", 1123 x->ealg->alg_name, 1124 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 1125 goto error; 1126 } 1127 1128 aead = crypto_alloc_aead(authenc_name, 0, 0); 1129 err = PTR_ERR(aead); 1130 if (IS_ERR(aead)) 1131 goto error; 1132 1133 x->data = aead; 1134 1135 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 1136 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 1137 err = -ENOMEM; 1138 key = kmalloc(keylen, GFP_KERNEL); 1139 if (!key) 1140 goto error; 1141 1142 p = key; 1143 rta = (void *)p; 1144 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 1145 rta->rta_len = RTA_LENGTH(sizeof(*param)); 1146 param = RTA_DATA(rta); 1147 p += RTA_SPACE(sizeof(*param)); 1148 1149 if (x->aalg) { 1150 struct xfrm_algo_desc *aalg_desc; 1151 1152 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 1153 p += (x->aalg->alg_key_len + 7) / 8; 1154 1155 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 1156 BUG_ON(!aalg_desc); 1157 1158 err = -EINVAL; 1159 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 1160 crypto_aead_authsize(aead)) { 1161 pr_info("ESP: %s digestsize %u != %hu\n", 1162 x->aalg->alg_name, 1163 crypto_aead_authsize(aead), 1164 aalg_desc->uinfo.auth.icv_fullbits / 8); 1165 goto free_key; 1166 } 1167 1168 err = crypto_aead_setauthsize( 1169 aead, x->aalg->alg_trunc_len / 8); 1170 if (err) 1171 goto free_key; 1172 } 1173 1174 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 1175 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 1176 1177 err = crypto_aead_setkey(aead, key, keylen); 1178 1179free_key: 1180 kfree(key); 1181 1182error: 1183 return err; 1184} 1185 1186static int esp6_init_state(struct xfrm_state *x) 1187{ 1188 struct crypto_aead *aead; 1189 u32 align; 1190 int err; 1191 1192 x->data = NULL; 1193 1194 if (x->aead) 1195 err = esp_init_aead(x); 1196 else 1197 err = esp_init_authenc(x); 1198 1199 if (err) 1200 goto error; 1201 1202 aead = x->data; 1203 1204 x->props.header_len = sizeof(struct ip_esp_hdr) + 1205 crypto_aead_ivsize(aead); 1206 switch (x->props.mode) { 1207 case XFRM_MODE_BEET: 1208 if (x->sel.family != AF_INET6) 1209 x->props.header_len += IPV4_BEET_PHMAXLEN + 1210 (sizeof(struct ipv6hdr) - sizeof(struct iphdr)); 1211 break; 1212 default: 1213 case XFRM_MODE_TRANSPORT: 1214 break; 1215 case XFRM_MODE_TUNNEL: 1216 x->props.header_len += sizeof(struct ipv6hdr); 1217 break; 1218 } 1219 1220 if (x->encap) { 1221 struct xfrm_encap_tmpl *encap = x->encap; 1222 1223 switch (encap->encap_type) { 1224 default: 1225 err = -EINVAL; 1226 goto error; 1227 case UDP_ENCAP_ESPINUDP: 1228 x->props.header_len += sizeof(struct udphdr); 1229 break; 1230 case UDP_ENCAP_ESPINUDP_NON_IKE: 1231 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 1232 break; 1233#ifdef CONFIG_INET6_ESPINTCP 1234 case TCP_ENCAP_ESPINTCP: 1235 /* only the length field, TCP encap is done by 1236 * the socket 1237 */ 1238 x->props.header_len += 2; 1239 break; 1240#endif 1241 } 1242 } 1243 1244 align = ALIGN(crypto_aead_blocksize(aead), 4); 1245 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 1246 1247error: 1248 return err; 1249} 1250 1251static int esp6_rcv_cb(struct sk_buff *skb, int err) 1252{ 1253 return 0; 1254} 1255 1256static const struct xfrm_type esp6_type = { 1257 .description = "ESP6", 1258 .owner = THIS_MODULE, 1259 .proto = IPPROTO_ESP, 1260 .flags = XFRM_TYPE_REPLAY_PROT, 1261 .init_state = esp6_init_state, 1262 .destructor = esp6_destroy, 1263 .input = esp6_input, 1264 .output = esp6_output, 1265 .hdr_offset = xfrm6_find_1stfragopt, 1266}; 1267 1268static struct xfrm6_protocol esp6_protocol = { 1269 .handler = xfrm6_rcv, 1270 .input_handler = xfrm_input, 1271 .cb_handler = esp6_rcv_cb, 1272 .err_handler = esp6_err, 1273 .priority = 0, 1274}; 1275 1276static int __init esp6_init(void) 1277{ 1278 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) { 1279 pr_info("%s: can't add xfrm type\n", __func__); 1280 return -EAGAIN; 1281 } 1282 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) { 1283 pr_info("%s: can't add protocol\n", __func__); 1284 xfrm_unregister_type(&esp6_type, AF_INET6); 1285 return -EAGAIN; 1286 } 1287 1288 return 0; 1289} 1290 1291static void __exit esp6_fini(void) 1292{ 1293 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0) 1294 pr_info("%s: can't remove protocol\n", __func__); 1295 xfrm_unregister_type(&esp6_type, AF_INET6); 1296} 1297 1298module_init(esp6_init); 1299module_exit(esp6_fini); 1300 1301MODULE_LICENSE("GPL"); 1302MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP); 1303