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, struct sk_buff *skb) 116{ 117 struct crypto_aead *aead = x->data; 118 int extralen = 0; 119 u8 *iv; 120 struct aead_request *req; 121 struct scatterlist *sg; 122 123 if (x->props.flags & XFRM_STATE_ESN) 124 extralen += sizeof(struct esp_output_extra); 125 126 iv = esp_tmp_iv(aead, tmp, extralen); 127 req = esp_tmp_req(aead, iv); 128 129 /* Unref skb_frag_pages in the src scatterlist if necessary. 130 * Skip the first sg which comes from skb->data. 131 */ 132 if (req->src != req->dst) 133 for (sg = sg_next(req->src); sg; sg = sg_next(sg)) 134 skb_page_unref(skb, sg_page(sg), false); 135} 136 137#ifdef CONFIG_INET6_ESPINTCP 138struct esp_tcp_sk { 139 struct sock *sk; 140 struct rcu_head rcu; 141}; 142 143static void esp_free_tcp_sk(struct rcu_head *head) 144{ 145 struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu); 146 147 sock_put(esk->sk); 148 kfree(esk); 149} 150 151static struct sock *esp6_find_tcp_sk(struct xfrm_state *x) 152{ 153 struct xfrm_encap_tmpl *encap = x->encap; 154 struct net *net = xs_net(x); 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(net, net->ipv4.tcp_death_row.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(void *data, int err) 282{ 283 struct sk_buff *skb = 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, skb); 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 * accommodate 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(void *data, int err) 372{ 373 struct sk_buff *skb = data; 374 375 esp_output_restore_header(skb); 376 esp_output_done(data, 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, skb); 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 crypto_aead *aead = x->data; 746 int alen, hlen, elen; 747 int padlen, trimlen; 748 __wsum csumdiff; 749 u8 nexthdr[2]; 750 int ret; 751 752 alen = crypto_aead_authsize(aead); 753 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 754 elen = skb->len - hlen; 755 756 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2); 757 BUG_ON(ret); 758 759 ret = -EINVAL; 760 padlen = nexthdr[0]; 761 if (padlen + 2 + alen >= elen) { 762 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", 763 padlen + 2, elen - alen); 764 goto out; 765 } 766 767 trimlen = alen + padlen + 2; 768 if (skb->ip_summed == CHECKSUM_COMPLETE) { 769 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); 770 skb->csum = csum_block_sub(skb->csum, csumdiff, 771 skb->len - trimlen); 772 } 773 ret = pskb_trim(skb, skb->len - trimlen); 774 if (unlikely(ret)) 775 return ret; 776 777 ret = nexthdr[1]; 778 779out: 780 return ret; 781} 782 783int esp6_input_done2(struct sk_buff *skb, int err) 784{ 785 struct xfrm_state *x = xfrm_input_state(skb); 786 struct xfrm_offload *xo = xfrm_offload(skb); 787 struct crypto_aead *aead = x->data; 788 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 789 int hdr_len = skb_network_header_len(skb); 790 791 if (!xo || !(xo->flags & CRYPTO_DONE)) 792 kfree(ESP_SKB_CB(skb)->tmp); 793 794 if (unlikely(err)) 795 goto out; 796 797 err = esp_remove_trailer(skb); 798 if (unlikely(err < 0)) 799 goto out; 800 801 if (x->encap) { 802 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 803 int offset = skb_network_offset(skb) + sizeof(*ip6h); 804 struct xfrm_encap_tmpl *encap = x->encap; 805 u8 nexthdr = ip6h->nexthdr; 806 __be16 frag_off, source; 807 struct udphdr *uh; 808 struct tcphdr *th; 809 810 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); 811 if (offset == -1) { 812 err = -EINVAL; 813 goto out; 814 } 815 816 uh = (void *)(skb->data + offset); 817 th = (void *)(skb->data + offset); 818 hdr_len += offset; 819 820 switch (x->encap->encap_type) { 821 case TCP_ENCAP_ESPINTCP: 822 source = th->source; 823 break; 824 case UDP_ENCAP_ESPINUDP: 825 case UDP_ENCAP_ESPINUDP_NON_IKE: 826 source = uh->source; 827 break; 828 default: 829 WARN_ON_ONCE(1); 830 err = -EINVAL; 831 goto out; 832 } 833 834 /* 835 * 1) if the NAT-T peer's IP or port changed then 836 * advertise the change to the keying daemon. 837 * This is an inbound SA, so just compare 838 * SRC ports. 839 */ 840 if (!ipv6_addr_equal(&ip6h->saddr, &x->props.saddr.in6) || 841 source != encap->encap_sport) { 842 xfrm_address_t ipaddr; 843 844 memcpy(&ipaddr.a6, &ip6h->saddr.s6_addr, sizeof(ipaddr.a6)); 845 km_new_mapping(x, &ipaddr, source); 846 847 /* XXX: perhaps add an extra 848 * policy check here, to see 849 * if we should allow or 850 * reject a packet from a 851 * different source 852 * address/port. 853 */ 854 } 855 856 /* 857 * 2) ignore UDP/TCP checksums in case 858 * of NAT-T in Transport Mode, or 859 * perform other post-processing fixes 860 * as per draft-ietf-ipsec-udp-encaps-06, 861 * section 3.1.2 862 */ 863 if (x->props.mode == XFRM_MODE_TRANSPORT) 864 skb->ip_summed = CHECKSUM_UNNECESSARY; 865 } 866 867 skb_postpull_rcsum(skb, skb_network_header(skb), 868 skb_network_header_len(skb)); 869 skb_pull_rcsum(skb, hlen); 870 if (x->props.mode == XFRM_MODE_TUNNEL) 871 skb_reset_transport_header(skb); 872 else 873 skb_set_transport_header(skb, -hdr_len); 874 875 /* RFC4303: Drop dummy packets without any error */ 876 if (err == IPPROTO_NONE) 877 err = -EINVAL; 878 879out: 880 return err; 881} 882EXPORT_SYMBOL_GPL(esp6_input_done2); 883 884static void esp_input_done(void *data, int err) 885{ 886 struct sk_buff *skb = data; 887 888 xfrm_input_resume(skb, esp6_input_done2(skb, err)); 889} 890 891static void esp_input_restore_header(struct sk_buff *skb) 892{ 893 esp_restore_header(skb, 0); 894 __skb_pull(skb, 4); 895} 896 897static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) 898{ 899 struct xfrm_state *x = xfrm_input_state(skb); 900 901 /* For ESN we move the header forward by 4 bytes to 902 * accommodate the high bits. We will move it back after 903 * decryption. 904 */ 905 if ((x->props.flags & XFRM_STATE_ESN)) { 906 struct ip_esp_hdr *esph = skb_push(skb, 4); 907 908 *seqhi = esph->spi; 909 esph->spi = esph->seq_no; 910 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; 911 } 912} 913 914static void esp_input_done_esn(void *data, int err) 915{ 916 struct sk_buff *skb = data; 917 918 esp_input_restore_header(skb); 919 esp_input_done(data, err); 920} 921 922static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) 923{ 924 struct crypto_aead *aead = x->data; 925 struct aead_request *req; 926 struct sk_buff *trailer; 927 int ivlen = crypto_aead_ivsize(aead); 928 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen; 929 int nfrags; 930 int assoclen; 931 int seqhilen; 932 int ret = 0; 933 void *tmp; 934 __be32 *seqhi; 935 u8 *iv; 936 struct scatterlist *sg; 937 938 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) { 939 ret = -EINVAL; 940 goto out; 941 } 942 943 if (elen <= 0) { 944 ret = -EINVAL; 945 goto out; 946 } 947 948 assoclen = sizeof(struct ip_esp_hdr); 949 seqhilen = 0; 950 951 if (x->props.flags & XFRM_STATE_ESN) { 952 seqhilen += sizeof(__be32); 953 assoclen += seqhilen; 954 } 955 956 if (!skb_cloned(skb)) { 957 if (!skb_is_nonlinear(skb)) { 958 nfrags = 1; 959 960 goto skip_cow; 961 } else if (!skb_has_frag_list(skb)) { 962 nfrags = skb_shinfo(skb)->nr_frags; 963 nfrags++; 964 965 goto skip_cow; 966 } 967 } 968 969 nfrags = skb_cow_data(skb, 0, &trailer); 970 if (nfrags < 0) { 971 ret = -EINVAL; 972 goto out; 973 } 974 975skip_cow: 976 ret = -ENOMEM; 977 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 978 if (!tmp) 979 goto out; 980 981 ESP_SKB_CB(skb)->tmp = tmp; 982 seqhi = esp_tmp_extra(tmp); 983 iv = esp_tmp_iv(aead, tmp, seqhilen); 984 req = esp_tmp_req(aead, iv); 985 sg = esp_req_sg(aead, req); 986 987 esp_input_set_header(skb, seqhi); 988 989 sg_init_table(sg, nfrags); 990 ret = skb_to_sgvec(skb, sg, 0, skb->len); 991 if (unlikely(ret < 0)) { 992 kfree(tmp); 993 goto out; 994 } 995 996 skb->ip_summed = CHECKSUM_NONE; 997 998 if ((x->props.flags & XFRM_STATE_ESN)) 999 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 1000 else 1001 aead_request_set_callback(req, 0, esp_input_done, skb); 1002 1003 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 1004 aead_request_set_ad(req, assoclen); 1005 1006 ret = crypto_aead_decrypt(req); 1007 if (ret == -EINPROGRESS) 1008 goto out; 1009 1010 if ((x->props.flags & XFRM_STATE_ESN)) 1011 esp_input_restore_header(skb); 1012 1013 ret = esp6_input_done2(skb, ret); 1014 1015out: 1016 return ret; 1017} 1018 1019static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 1020 u8 type, u8 code, int offset, __be32 info) 1021{ 1022 struct net *net = dev_net(skb->dev); 1023 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 1024 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset); 1025 struct xfrm_state *x; 1026 1027 if (type != ICMPV6_PKT_TOOBIG && 1028 type != NDISC_REDIRECT) 1029 return 0; 1030 1031 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 1032 esph->spi, IPPROTO_ESP, AF_INET6); 1033 if (!x) 1034 return 0; 1035 1036 if (type == NDISC_REDIRECT) 1037 ip6_redirect(skb, net, skb->dev->ifindex, 0, 1038 sock_net_uid(net, NULL)); 1039 else 1040 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 1041 xfrm_state_put(x); 1042 1043 return 0; 1044} 1045 1046static void esp6_destroy(struct xfrm_state *x) 1047{ 1048 struct crypto_aead *aead = x->data; 1049 1050 if (!aead) 1051 return; 1052 1053 crypto_free_aead(aead); 1054} 1055 1056static int esp_init_aead(struct xfrm_state *x, struct netlink_ext_ack *extack) 1057{ 1058 char aead_name[CRYPTO_MAX_ALG_NAME]; 1059 struct crypto_aead *aead; 1060 int err; 1061 1062 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 1063 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) { 1064 NL_SET_ERR_MSG(extack, "Algorithm name is too long"); 1065 return -ENAMETOOLONG; 1066 } 1067 1068 aead = crypto_alloc_aead(aead_name, 0, 0); 1069 err = PTR_ERR(aead); 1070 if (IS_ERR(aead)) 1071 goto error; 1072 1073 x->data = aead; 1074 1075 err = crypto_aead_setkey(aead, x->aead->alg_key, 1076 (x->aead->alg_key_len + 7) / 8); 1077 if (err) 1078 goto error; 1079 1080 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 1081 if (err) 1082 goto error; 1083 1084 return 0; 1085 1086error: 1087 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations"); 1088 return err; 1089} 1090 1091static int esp_init_authenc(struct xfrm_state *x, 1092 struct netlink_ext_ack *extack) 1093{ 1094 struct crypto_aead *aead; 1095 struct crypto_authenc_key_param *param; 1096 struct rtattr *rta; 1097 char *key; 1098 char *p; 1099 char authenc_name[CRYPTO_MAX_ALG_NAME]; 1100 unsigned int keylen; 1101 int err; 1102 1103 err = -ENAMETOOLONG; 1104 1105 if ((x->props.flags & XFRM_STATE_ESN)) { 1106 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 1107 "%s%sauthencesn(%s,%s)%s", 1108 x->geniv ?: "", x->geniv ? "(" : "", 1109 x->aalg ? x->aalg->alg_name : "digest_null", 1110 x->ealg->alg_name, 1111 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) { 1112 NL_SET_ERR_MSG(extack, "Algorithm name is too long"); 1113 goto error; 1114 } 1115 } else { 1116 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 1117 "%s%sauthenc(%s,%s)%s", 1118 x->geniv ?: "", x->geniv ? "(" : "", 1119 x->aalg ? x->aalg->alg_name : "digest_null", 1120 x->ealg->alg_name, 1121 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) { 1122 NL_SET_ERR_MSG(extack, "Algorithm name is too long"); 1123 goto error; 1124 } 1125 } 1126 1127 aead = crypto_alloc_aead(authenc_name, 0, 0); 1128 err = PTR_ERR(aead); 1129 if (IS_ERR(aead)) { 1130 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations"); 1131 goto error; 1132 } 1133 1134 x->data = aead; 1135 1136 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 1137 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 1138 err = -ENOMEM; 1139 key = kmalloc(keylen, GFP_KERNEL); 1140 if (!key) 1141 goto error; 1142 1143 p = key; 1144 rta = (void *)p; 1145 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 1146 rta->rta_len = RTA_LENGTH(sizeof(*param)); 1147 param = RTA_DATA(rta); 1148 p += RTA_SPACE(sizeof(*param)); 1149 1150 if (x->aalg) { 1151 struct xfrm_algo_desc *aalg_desc; 1152 1153 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 1154 p += (x->aalg->alg_key_len + 7) / 8; 1155 1156 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 1157 BUG_ON(!aalg_desc); 1158 1159 err = -EINVAL; 1160 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 1161 crypto_aead_authsize(aead)) { 1162 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations"); 1163 goto free_key; 1164 } 1165 1166 err = crypto_aead_setauthsize( 1167 aead, x->aalg->alg_trunc_len / 8); 1168 if (err) { 1169 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations"); 1170 goto free_key; 1171 } 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, struct netlink_ext_ack *extack) 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, extack); 1196 } else if (x->ealg) { 1197 err = esp_init_authenc(x, extack); 1198 } else { 1199 NL_SET_ERR_MSG(extack, "ESP: AEAD or CRYPT must be provided"); 1200 err = -EINVAL; 1201 } 1202 1203 if (err) 1204 goto error; 1205 1206 aead = x->data; 1207 1208 x->props.header_len = sizeof(struct ip_esp_hdr) + 1209 crypto_aead_ivsize(aead); 1210 switch (x->props.mode) { 1211 case XFRM_MODE_BEET: 1212 if (x->sel.family != AF_INET6) 1213 x->props.header_len += IPV4_BEET_PHMAXLEN + 1214 (sizeof(struct ipv6hdr) - sizeof(struct iphdr)); 1215 break; 1216 default: 1217 case XFRM_MODE_TRANSPORT: 1218 break; 1219 case XFRM_MODE_TUNNEL: 1220 x->props.header_len += sizeof(struct ipv6hdr); 1221 break; 1222 } 1223 1224 if (x->encap) { 1225 struct xfrm_encap_tmpl *encap = x->encap; 1226 1227 switch (encap->encap_type) { 1228 default: 1229 NL_SET_ERR_MSG(extack, "Unsupported encapsulation type for ESP"); 1230 err = -EINVAL; 1231 goto error; 1232 case UDP_ENCAP_ESPINUDP: 1233 x->props.header_len += sizeof(struct udphdr); 1234 break; 1235 case UDP_ENCAP_ESPINUDP_NON_IKE: 1236 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 1237 break; 1238#ifdef CONFIG_INET6_ESPINTCP 1239 case TCP_ENCAP_ESPINTCP: 1240 /* only the length field, TCP encap is done by 1241 * the socket 1242 */ 1243 x->props.header_len += 2; 1244 break; 1245#endif 1246 } 1247 } 1248 1249 align = ALIGN(crypto_aead_blocksize(aead), 4); 1250 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 1251 1252error: 1253 return err; 1254} 1255 1256static int esp6_rcv_cb(struct sk_buff *skb, int err) 1257{ 1258 return 0; 1259} 1260 1261static const struct xfrm_type esp6_type = { 1262 .owner = THIS_MODULE, 1263 .proto = IPPROTO_ESP, 1264 .flags = XFRM_TYPE_REPLAY_PROT, 1265 .init_state = esp6_init_state, 1266 .destructor = esp6_destroy, 1267 .input = esp6_input, 1268 .output = esp6_output, 1269}; 1270 1271static struct xfrm6_protocol esp6_protocol = { 1272 .handler = xfrm6_rcv, 1273 .input_handler = xfrm_input, 1274 .cb_handler = esp6_rcv_cb, 1275 .err_handler = esp6_err, 1276 .priority = 0, 1277}; 1278 1279static int __init esp6_init(void) 1280{ 1281 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) { 1282 pr_info("%s: can't add xfrm type\n", __func__); 1283 return -EAGAIN; 1284 } 1285 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) { 1286 pr_info("%s: can't add protocol\n", __func__); 1287 xfrm_unregister_type(&esp6_type, AF_INET6); 1288 return -EAGAIN; 1289 } 1290 1291 return 0; 1292} 1293 1294static void __exit esp6_fini(void) 1295{ 1296 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0) 1297 pr_info("%s: can't remove protocol\n", __func__); 1298 xfrm_unregister_type(&esp6_type, AF_INET6); 1299} 1300 1301module_init(esp6_init); 1302module_exit(esp6_fini); 1303 1304MODULE_DESCRIPTION("IPv6 ESP transformation helpers"); 1305MODULE_LICENSE("GPL"); 1306MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP); 1307