1 #define pr_fmt(fmt) "IPsec: " fmt 2 3 #include <crypto/aead.h> 4 #include <crypto/authenc.h> 5 #include <linux/err.h> 6 #include <linux/module.h> 7 #include <net/ip.h> 8 #include <net/xfrm.h> 9 #include <net/esp.h> 10 #include <linux/scatterlist.h> 11 #include <linux/kernel.h> 12 #include <linux/pfkeyv2.h> 13 #include <linux/rtnetlink.h> 14 #include <linux/slab.h> 15 #include <linux/spinlock.h> 16 #include <linux/in6.h> 17 #include <net/icmp.h> 18 #include <net/protocol.h> 19 #include <net/udp.h> 20 21 struct esp_skb_cb { 22 struct xfrm_skb_cb xfrm; 23 void *tmp; 24 }; 25 26 struct esp_output_extra { 27 __be32 seqhi; 28 u32 esphoff; 29 }; 30 31 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) 32 33 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu); 34 35 /* 36 * Allocate an AEAD request structure with extra space for SG and IV. 37 * 38 * For alignment considerations the IV is placed at the front, followed 39 * by the request and finally the SG list. 40 * 41 * TODO: Use spare space in skb for this where possible. 42 */ 43 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen) 44 { 45 unsigned int len; 46 47 len = extralen; 48 49 len += crypto_aead_ivsize(aead); 50 51 if (len) { 52 len += crypto_aead_alignmask(aead) & 53 ~(crypto_tfm_ctx_alignment() - 1); 54 len = ALIGN(len, crypto_tfm_ctx_alignment()); 55 } 56 57 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); 58 len = ALIGN(len, __alignof__(struct scatterlist)); 59 60 len += sizeof(struct scatterlist) * nfrags; 61 62 return kmalloc(len, GFP_ATOMIC); 63 } 64 65 static inline void *esp_tmp_extra(void *tmp) 66 { 67 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra)); 68 } 69 70 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen) 71 { 72 return crypto_aead_ivsize(aead) ? 73 PTR_ALIGN((u8 *)tmp + extralen, 74 crypto_aead_alignmask(aead) + 1) : tmp + extralen; 75 } 76 77 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) 78 { 79 struct aead_request *req; 80 81 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), 82 crypto_tfm_ctx_alignment()); 83 aead_request_set_tfm(req, aead); 84 return req; 85 } 86 87 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, 88 struct aead_request *req) 89 { 90 return (void *)ALIGN((unsigned long)(req + 1) + 91 crypto_aead_reqsize(aead), 92 __alignof__(struct scatterlist)); 93 } 94 95 static void esp_output_done(struct crypto_async_request *base, int err) 96 { 97 struct sk_buff *skb = base->data; 98 99 kfree(ESP_SKB_CB(skb)->tmp); 100 xfrm_output_resume(skb, err); 101 } 102 103 /* Move ESP header back into place. */ 104 static void esp_restore_header(struct sk_buff *skb, unsigned int offset) 105 { 106 struct ip_esp_hdr *esph = (void *)(skb->data + offset); 107 void *tmp = ESP_SKB_CB(skb)->tmp; 108 __be32 *seqhi = esp_tmp_extra(tmp); 109 110 esph->seq_no = esph->spi; 111 esph->spi = *seqhi; 112 } 113 114 static void esp_output_restore_header(struct sk_buff *skb) 115 { 116 void *tmp = ESP_SKB_CB(skb)->tmp; 117 struct esp_output_extra *extra = esp_tmp_extra(tmp); 118 119 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - 120 sizeof(__be32)); 121 } 122 123 static void esp_output_done_esn(struct crypto_async_request *base, int err) 124 { 125 struct sk_buff *skb = base->data; 126 127 esp_output_restore_header(skb); 128 esp_output_done(base, err); 129 } 130 131 static int esp_output(struct xfrm_state *x, struct sk_buff *skb) 132 { 133 int err; 134 struct esp_output_extra *extra; 135 struct ip_esp_hdr *esph; 136 struct crypto_aead *aead; 137 struct aead_request *req; 138 struct scatterlist *sg; 139 struct sk_buff *trailer; 140 void *tmp; 141 u8 *iv; 142 u8 *tail; 143 int blksize; 144 int clen; 145 int alen; 146 int plen; 147 int ivlen; 148 int tfclen; 149 int nfrags; 150 int assoclen; 151 int extralen; 152 __be64 seqno; 153 154 /* skb is pure payload to encrypt */ 155 156 aead = x->data; 157 alen = crypto_aead_authsize(aead); 158 ivlen = crypto_aead_ivsize(aead); 159 160 tfclen = 0; 161 if (x->tfcpad) { 162 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); 163 u32 padto; 164 165 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); 166 if (skb->len < padto) 167 tfclen = padto - skb->len; 168 } 169 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 170 clen = ALIGN(skb->len + 2 + tfclen, blksize); 171 plen = clen - skb->len - tfclen; 172 173 err = skb_cow_data(skb, tfclen + plen + alen, &trailer); 174 if (err < 0) 175 goto error; 176 nfrags = err; 177 178 assoclen = sizeof(*esph); 179 extralen = 0; 180 181 if (x->props.flags & XFRM_STATE_ESN) { 182 extralen += sizeof(*extra); 183 assoclen += sizeof(__be32); 184 } 185 186 tmp = esp_alloc_tmp(aead, nfrags, extralen); 187 if (!tmp) { 188 err = -ENOMEM; 189 goto error; 190 } 191 192 extra = esp_tmp_extra(tmp); 193 iv = esp_tmp_iv(aead, tmp, extralen); 194 req = esp_tmp_req(aead, iv); 195 sg = esp_req_sg(aead, req); 196 197 /* Fill padding... */ 198 tail = skb_tail_pointer(trailer); 199 if (tfclen) { 200 memset(tail, 0, tfclen); 201 tail += tfclen; 202 } 203 do { 204 int i; 205 for (i = 0; i < plen - 2; i++) 206 tail[i] = i + 1; 207 } while (0); 208 tail[plen - 2] = plen - 2; 209 tail[plen - 1] = *skb_mac_header(skb); 210 pskb_put(skb, trailer, clen - skb->len + alen); 211 212 skb_push(skb, -skb_network_offset(skb)); 213 esph = ip_esp_hdr(skb); 214 *skb_mac_header(skb) = IPPROTO_ESP; 215 216 /* this is non-NULL only with UDP Encapsulation */ 217 if (x->encap) { 218 struct xfrm_encap_tmpl *encap = x->encap; 219 struct udphdr *uh; 220 __be32 *udpdata32; 221 __be16 sport, dport; 222 int encap_type; 223 224 spin_lock_bh(&x->lock); 225 sport = encap->encap_sport; 226 dport = encap->encap_dport; 227 encap_type = encap->encap_type; 228 spin_unlock_bh(&x->lock); 229 230 uh = (struct udphdr *)esph; 231 uh->source = sport; 232 uh->dest = dport; 233 uh->len = htons(skb->len - skb_transport_offset(skb)); 234 uh->check = 0; 235 236 switch (encap_type) { 237 default: 238 case UDP_ENCAP_ESPINUDP: 239 esph = (struct ip_esp_hdr *)(uh + 1); 240 break; 241 case UDP_ENCAP_ESPINUDP_NON_IKE: 242 udpdata32 = (__be32 *)(uh + 1); 243 udpdata32[0] = udpdata32[1] = 0; 244 esph = (struct ip_esp_hdr *)(udpdata32 + 2); 245 break; 246 } 247 248 *skb_mac_header(skb) = IPPROTO_UDP; 249 } 250 251 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); 252 253 aead_request_set_callback(req, 0, esp_output_done, skb); 254 255 /* For ESN we move the header forward by 4 bytes to 256 * accomodate the high bits. We will move it back after 257 * encryption. 258 */ 259 if ((x->props.flags & XFRM_STATE_ESN)) { 260 extra->esphoff = (unsigned char *)esph - 261 skb_transport_header(skb); 262 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); 263 extra->seqhi = esph->spi; 264 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi); 265 aead_request_set_callback(req, 0, esp_output_done_esn, skb); 266 } 267 268 esph->spi = x->id.spi; 269 270 sg_init_table(sg, nfrags); 271 skb_to_sgvec(skb, sg, 272 (unsigned char *)esph - skb->data, 273 assoclen + ivlen + clen + alen); 274 275 aead_request_set_crypt(req, sg, sg, ivlen + clen, iv); 276 aead_request_set_ad(req, assoclen); 277 278 seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + 279 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); 280 281 memset(iv, 0, ivlen); 282 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8), 283 min(ivlen, 8)); 284 285 ESP_SKB_CB(skb)->tmp = tmp; 286 err = crypto_aead_encrypt(req); 287 288 switch (err) { 289 case -EINPROGRESS: 290 goto error; 291 292 case -EBUSY: 293 err = NET_XMIT_DROP; 294 break; 295 296 case 0: 297 if ((x->props.flags & XFRM_STATE_ESN)) 298 esp_output_restore_header(skb); 299 } 300 301 kfree(tmp); 302 303 error: 304 return err; 305 } 306 307 static int esp_input_done2(struct sk_buff *skb, int err) 308 { 309 const struct iphdr *iph; 310 struct xfrm_state *x = xfrm_input_state(skb); 311 struct crypto_aead *aead = x->data; 312 int alen = crypto_aead_authsize(aead); 313 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); 314 int elen = skb->len - hlen; 315 int ihl; 316 u8 nexthdr[2]; 317 int padlen; 318 319 kfree(ESP_SKB_CB(skb)->tmp); 320 321 if (unlikely(err)) 322 goto out; 323 324 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) 325 BUG(); 326 327 err = -EINVAL; 328 padlen = nexthdr[0]; 329 if (padlen + 2 + alen >= elen) 330 goto out; 331 332 /* ... check padding bits here. Silly. :-) */ 333 334 iph = ip_hdr(skb); 335 ihl = iph->ihl * 4; 336 337 if (x->encap) { 338 struct xfrm_encap_tmpl *encap = x->encap; 339 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); 340 341 /* 342 * 1) if the NAT-T peer's IP or port changed then 343 * advertize the change to the keying daemon. 344 * This is an inbound SA, so just compare 345 * SRC ports. 346 */ 347 if (iph->saddr != x->props.saddr.a4 || 348 uh->source != encap->encap_sport) { 349 xfrm_address_t ipaddr; 350 351 ipaddr.a4 = iph->saddr; 352 km_new_mapping(x, &ipaddr, uh->source); 353 354 /* XXX: perhaps add an extra 355 * policy check here, to see 356 * if we should allow or 357 * reject a packet from a 358 * different source 359 * address/port. 360 */ 361 } 362 363 /* 364 * 2) ignore UDP/TCP checksums in case 365 * of NAT-T in Transport Mode, or 366 * perform other post-processing fixes 367 * as per draft-ietf-ipsec-udp-encaps-06, 368 * section 3.1.2 369 */ 370 if (x->props.mode == XFRM_MODE_TRANSPORT) 371 skb->ip_summed = CHECKSUM_UNNECESSARY; 372 } 373 374 pskb_trim(skb, skb->len - alen - padlen - 2); 375 __skb_pull(skb, hlen); 376 if (x->props.mode == XFRM_MODE_TUNNEL) 377 skb_reset_transport_header(skb); 378 else 379 skb_set_transport_header(skb, -ihl); 380 381 err = nexthdr[1]; 382 383 /* RFC4303: Drop dummy packets without any error */ 384 if (err == IPPROTO_NONE) 385 err = -EINVAL; 386 387 out: 388 return err; 389 } 390 391 static void esp_input_done(struct crypto_async_request *base, int err) 392 { 393 struct sk_buff *skb = base->data; 394 395 xfrm_input_resume(skb, esp_input_done2(skb, err)); 396 } 397 398 static void esp_input_restore_header(struct sk_buff *skb) 399 { 400 esp_restore_header(skb, 0); 401 __skb_pull(skb, 4); 402 } 403 404 static void esp_input_done_esn(struct crypto_async_request *base, int err) 405 { 406 struct sk_buff *skb = base->data; 407 408 esp_input_restore_header(skb); 409 esp_input_done(base, err); 410 } 411 412 /* 413 * Note: detecting truncated vs. non-truncated authentication data is very 414 * expensive, so we only support truncated data, which is the recommended 415 * and common case. 416 */ 417 static int esp_input(struct xfrm_state *x, struct sk_buff *skb) 418 { 419 struct ip_esp_hdr *esph; 420 struct crypto_aead *aead = x->data; 421 struct aead_request *req; 422 struct sk_buff *trailer; 423 int ivlen = crypto_aead_ivsize(aead); 424 int elen = skb->len - sizeof(*esph) - ivlen; 425 int nfrags; 426 int assoclen; 427 int seqhilen; 428 __be32 *seqhi; 429 void *tmp; 430 u8 *iv; 431 struct scatterlist *sg; 432 int err = -EINVAL; 433 434 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) 435 goto out; 436 437 if (elen <= 0) 438 goto out; 439 440 err = skb_cow_data(skb, 0, &trailer); 441 if (err < 0) 442 goto out; 443 444 nfrags = err; 445 446 assoclen = sizeof(*esph); 447 seqhilen = 0; 448 449 if (x->props.flags & XFRM_STATE_ESN) { 450 seqhilen += sizeof(__be32); 451 assoclen += seqhilen; 452 } 453 454 err = -ENOMEM; 455 tmp = esp_alloc_tmp(aead, nfrags, seqhilen); 456 if (!tmp) 457 goto out; 458 459 ESP_SKB_CB(skb)->tmp = tmp; 460 seqhi = esp_tmp_extra(tmp); 461 iv = esp_tmp_iv(aead, tmp, seqhilen); 462 req = esp_tmp_req(aead, iv); 463 sg = esp_req_sg(aead, req); 464 465 skb->ip_summed = CHECKSUM_NONE; 466 467 esph = (struct ip_esp_hdr *)skb->data; 468 469 aead_request_set_callback(req, 0, esp_input_done, skb); 470 471 /* For ESN we move the header forward by 4 bytes to 472 * accomodate the high bits. We will move it back after 473 * decryption. 474 */ 475 if ((x->props.flags & XFRM_STATE_ESN)) { 476 esph = (void *)skb_push(skb, 4); 477 *seqhi = esph->spi; 478 esph->spi = esph->seq_no; 479 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.input.hi); 480 aead_request_set_callback(req, 0, esp_input_done_esn, skb); 481 } 482 483 sg_init_table(sg, nfrags); 484 skb_to_sgvec(skb, sg, 0, skb->len); 485 486 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); 487 aead_request_set_ad(req, assoclen); 488 489 err = crypto_aead_decrypt(req); 490 if (err == -EINPROGRESS) 491 goto out; 492 493 if ((x->props.flags & XFRM_STATE_ESN)) 494 esp_input_restore_header(skb); 495 496 err = esp_input_done2(skb, err); 497 498 out: 499 return err; 500 } 501 502 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) 503 { 504 struct crypto_aead *aead = x->data; 505 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); 506 unsigned int net_adj; 507 508 switch (x->props.mode) { 509 case XFRM_MODE_TRANSPORT: 510 case XFRM_MODE_BEET: 511 net_adj = sizeof(struct iphdr); 512 break; 513 case XFRM_MODE_TUNNEL: 514 net_adj = 0; 515 break; 516 default: 517 BUG(); 518 } 519 520 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - 521 net_adj) & ~(blksize - 1)) + net_adj - 2; 522 } 523 524 static int esp4_err(struct sk_buff *skb, u32 info) 525 { 526 struct net *net = dev_net(skb->dev); 527 const struct iphdr *iph = (const struct iphdr *)skb->data; 528 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); 529 struct xfrm_state *x; 530 531 switch (icmp_hdr(skb)->type) { 532 case ICMP_DEST_UNREACH: 533 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) 534 return 0; 535 case ICMP_REDIRECT: 536 break; 537 default: 538 return 0; 539 } 540 541 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 542 esph->spi, IPPROTO_ESP, AF_INET); 543 if (!x) 544 return 0; 545 546 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) 547 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0); 548 else 549 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0); 550 xfrm_state_put(x); 551 552 return 0; 553 } 554 555 static void esp_destroy(struct xfrm_state *x) 556 { 557 struct crypto_aead *aead = x->data; 558 559 if (!aead) 560 return; 561 562 crypto_free_aead(aead); 563 } 564 565 static int esp_init_aead(struct xfrm_state *x) 566 { 567 char aead_name[CRYPTO_MAX_ALG_NAME]; 568 struct crypto_aead *aead; 569 int err; 570 571 err = -ENAMETOOLONG; 572 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", 573 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) 574 goto error; 575 576 aead = crypto_alloc_aead(aead_name, 0, 0); 577 err = PTR_ERR(aead); 578 if (IS_ERR(aead)) 579 goto error; 580 581 x->data = aead; 582 583 err = crypto_aead_setkey(aead, x->aead->alg_key, 584 (x->aead->alg_key_len + 7) / 8); 585 if (err) 586 goto error; 587 588 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); 589 if (err) 590 goto error; 591 592 error: 593 return err; 594 } 595 596 static int esp_init_authenc(struct xfrm_state *x) 597 { 598 struct crypto_aead *aead; 599 struct crypto_authenc_key_param *param; 600 struct rtattr *rta; 601 char *key; 602 char *p; 603 char authenc_name[CRYPTO_MAX_ALG_NAME]; 604 unsigned int keylen; 605 int err; 606 607 err = -EINVAL; 608 if (!x->ealg) 609 goto error; 610 611 err = -ENAMETOOLONG; 612 613 if ((x->props.flags & XFRM_STATE_ESN)) { 614 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 615 "%s%sauthencesn(%s,%s)%s", 616 x->geniv ?: "", x->geniv ? "(" : "", 617 x->aalg ? x->aalg->alg_name : "digest_null", 618 x->ealg->alg_name, 619 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 620 goto error; 621 } else { 622 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, 623 "%s%sauthenc(%s,%s)%s", 624 x->geniv ?: "", x->geniv ? "(" : "", 625 x->aalg ? x->aalg->alg_name : "digest_null", 626 x->ealg->alg_name, 627 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) 628 goto error; 629 } 630 631 aead = crypto_alloc_aead(authenc_name, 0, 0); 632 err = PTR_ERR(aead); 633 if (IS_ERR(aead)) 634 goto error; 635 636 x->data = aead; 637 638 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + 639 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); 640 err = -ENOMEM; 641 key = kmalloc(keylen, GFP_KERNEL); 642 if (!key) 643 goto error; 644 645 p = key; 646 rta = (void *)p; 647 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 648 rta->rta_len = RTA_LENGTH(sizeof(*param)); 649 param = RTA_DATA(rta); 650 p += RTA_SPACE(sizeof(*param)); 651 652 if (x->aalg) { 653 struct xfrm_algo_desc *aalg_desc; 654 655 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); 656 p += (x->aalg->alg_key_len + 7) / 8; 657 658 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); 659 BUG_ON(!aalg_desc); 660 661 err = -EINVAL; 662 if (aalg_desc->uinfo.auth.icv_fullbits / 8 != 663 crypto_aead_authsize(aead)) { 664 pr_info("ESP: %s digestsize %u != %hu\n", 665 x->aalg->alg_name, 666 crypto_aead_authsize(aead), 667 aalg_desc->uinfo.auth.icv_fullbits / 8); 668 goto free_key; 669 } 670 671 err = crypto_aead_setauthsize( 672 aead, x->aalg->alg_trunc_len / 8); 673 if (err) 674 goto free_key; 675 } 676 677 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); 678 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); 679 680 err = crypto_aead_setkey(aead, key, keylen); 681 682 free_key: 683 kfree(key); 684 685 error: 686 return err; 687 } 688 689 static int esp_init_state(struct xfrm_state *x) 690 { 691 struct crypto_aead *aead; 692 u32 align; 693 int err; 694 695 x->data = NULL; 696 697 if (x->aead) 698 err = esp_init_aead(x); 699 else 700 err = esp_init_authenc(x); 701 702 if (err) 703 goto error; 704 705 aead = x->data; 706 707 x->props.header_len = sizeof(struct ip_esp_hdr) + 708 crypto_aead_ivsize(aead); 709 if (x->props.mode == XFRM_MODE_TUNNEL) 710 x->props.header_len += sizeof(struct iphdr); 711 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) 712 x->props.header_len += IPV4_BEET_PHMAXLEN; 713 if (x->encap) { 714 struct xfrm_encap_tmpl *encap = x->encap; 715 716 switch (encap->encap_type) { 717 default: 718 goto error; 719 case UDP_ENCAP_ESPINUDP: 720 x->props.header_len += sizeof(struct udphdr); 721 break; 722 case UDP_ENCAP_ESPINUDP_NON_IKE: 723 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); 724 break; 725 } 726 } 727 728 align = ALIGN(crypto_aead_blocksize(aead), 4); 729 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); 730 731 error: 732 return err; 733 } 734 735 static int esp4_rcv_cb(struct sk_buff *skb, int err) 736 { 737 return 0; 738 } 739 740 static const struct xfrm_type esp_type = 741 { 742 .description = "ESP4", 743 .owner = THIS_MODULE, 744 .proto = IPPROTO_ESP, 745 .flags = XFRM_TYPE_REPLAY_PROT, 746 .init_state = esp_init_state, 747 .destructor = esp_destroy, 748 .get_mtu = esp4_get_mtu, 749 .input = esp_input, 750 .output = esp_output 751 }; 752 753 static struct xfrm4_protocol esp4_protocol = { 754 .handler = xfrm4_rcv, 755 .input_handler = xfrm_input, 756 .cb_handler = esp4_rcv_cb, 757 .err_handler = esp4_err, 758 .priority = 0, 759 }; 760 761 static int __init esp4_init(void) 762 { 763 if (xfrm_register_type(&esp_type, AF_INET) < 0) { 764 pr_info("%s: can't add xfrm type\n", __func__); 765 return -EAGAIN; 766 } 767 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { 768 pr_info("%s: can't add protocol\n", __func__); 769 xfrm_unregister_type(&esp_type, AF_INET); 770 return -EAGAIN; 771 } 772 return 0; 773 } 774 775 static void __exit esp4_fini(void) 776 { 777 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) 778 pr_info("%s: can't remove protocol\n", __func__); 779 if (xfrm_unregister_type(&esp_type, AF_INET) < 0) 780 pr_info("%s: can't remove xfrm type\n", __func__); 781 } 782 783 module_init(esp4_init); 784 module_exit(esp4_fini); 785 MODULE_LICENSE("GPL"); 786 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); 787