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