net/ipv6/esp6.c

   1 /*
   2  * Copyright (C)2002 USAGI/WIDE Project
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  *
  17  * Authors
  18  *
  19  *      Mitsuru KANDA @USAGI       : IPv6 Support
  20  *      Kazunori MIYAZAWA @USAGI   :
  21  *      Kunihiro Ishiguro <kunihiro@ipinfusion.com>
  22  *
  23  *      This file is derived from net/ipv4/esp.c
  24  */
  25
  26 #define pr_fmt(fmt) "IPv6: " fmt
  27
  28 #include <crypto/aead.h>
  29 #include <crypto/authenc.h>
  30 #include <linux/err.h>
  31 #include <linux/module.h>
  32 #include <net/ip.h>
  33 #include <net/xfrm.h>
  34 #include <net/esp.h>
  35 #include <linux/scatterlist.h>
  36 #include <linux/kernel.h>
  37 #include <linux/pfkeyv2.h>
  38 #include <linux/random.h>
  39 #include <linux/slab.h>
  40 #include <linux/spinlock.h>
  41 #include <net/ip6_route.h>
  42 #include <net/icmp.h>
  43 #include <net/ipv6.h>
  44 #include <net/protocol.h>
  45 #include <linux/icmpv6.h>
  46
  47 #include <linux/highmem.h>
  48
  49 struct esp_skb_cb {
  50         struct xfrm_skb_cb xfrm;
  51         void *tmp;
  52 };
  53
  54 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
  55
  56 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
  57
  58 /*
  59  * Allocate an AEAD request structure with extra space for SG and IV.
  60  *
  61  * For alignment considerations the upper 32 bits of the sequence number are
  62  * placed at the front, if present. Followed by the IV, the request and finally
  63  * the SG list.
  64  *
  65  * TODO: Use spare space in skb for this where possible.
  66  */
  67 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
  68 {
  69         unsigned int len;
  70
  71         len = seqihlen;
  72
  73         len += crypto_aead_ivsize(aead);
  74
  75         if (len) {
  76                 len += crypto_aead_alignmask(aead) &
  77                        ~(crypto_tfm_ctx_alignment() - 1);
  78                 len = ALIGN(len, crypto_tfm_ctx_alignment());
  79         }
  80
  81         len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
  82         len = ALIGN(len, __alignof__(struct scatterlist));
  83
  84         len += sizeof(struct scatterlist) * nfrags;
  85
  86         return kmalloc(len, GFP_ATOMIC);
  87 }
  88
  89 static inline __be32 *esp_tmp_seqhi(void *tmp)
  90 {
  91         return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
  92 }
  93
  94 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
  95 {
  96         return crypto_aead_ivsize(aead) ?
  97                PTR_ALIGN((u8 *)tmp + seqhilen,
  98                          crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
  99 }
 100
 101 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
 102 {
 103         struct aead_request *req;
 104
 105         req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
 106                                 crypto_tfm_ctx_alignment());
 107         aead_request_set_tfm(req, aead);
 108         return req;
 109 }
 110
 111 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
 112                                              struct aead_request *req)
 113 {
 114         return (void *)ALIGN((unsigned long)(req + 1) +
 115                              crypto_aead_reqsize(aead),
 116                              __alignof__(struct scatterlist));
 117 }
 118
 119 static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
 120 {
 121         struct crypto_aead *aead = x->data;
 122         int seqhilen = 0;
 123         u8 *iv;
 124         struct aead_request *req;
 125         struct scatterlist *sg;
 126
 127         if (x->props.flags & XFRM_STATE_ESN)
 128                 seqhilen += sizeof(__be32);
 129
 130         iv = esp_tmp_iv(aead, tmp, seqhilen);
 131         req = esp_tmp_req(aead, iv);
 132
 133         /* Unref skb_frag_pages in the src scatterlist if necessary.
 134          * Skip the first sg which comes from skb->data.
 135          */
 136         if (req->src != req->dst)
 137                 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
 138                         put_page(sg_page(sg));
 139 }
 140
 141 static void esp_output_done(struct crypto_async_request *base, int err)
 142 {
 143         struct sk_buff *skb = base->data;
 144         struct xfrm_offload *xo = xfrm_offload(skb);
 145         void *tmp;
 146         struct xfrm_state *x;
 147
 148         if (xo && (xo->flags & XFRM_DEV_RESUME)) {
 149                 struct sec_path *sp = skb_sec_path(skb);
 150
 151                 x = sp->xvec[sp->len - 1];
 152         } else {
 153                 x = skb_dst(skb)->xfrm;
 154         }
 155
 156         tmp = ESP_SKB_CB(skb)->tmp;
 157         esp_ssg_unref(x, tmp);
 158         kfree(tmp);
 159
 160         if (xo && (xo->flags & XFRM_DEV_RESUME)) {
 161                 if (err) {
 162                         XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
 163                         kfree_skb(skb);
 164                         return;
 165                 }
 166
 167                 skb_push(skb, skb->data - skb_mac_header(skb));
 168                 secpath_reset(skb);
 169                 xfrm_dev_resume(skb);
 170         } else {
 171                 xfrm_output_resume(skb, err);
 172         }
 173 }
 174
 175 /* Move ESP header back into place. */
 176 static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
 177 {
 178         struct ip_esp_hdr *esph = (void *)(skb->data + offset);
 179         void *tmp = ESP_SKB_CB(skb)->tmp;
 180         __be32 *seqhi = esp_tmp_seqhi(tmp);
 181
 182         esph->seq_no = esph->spi;
 183         esph->spi = *seqhi;
 184 }
 185
 186 static void esp_output_restore_header(struct sk_buff *skb)
 187 {
 188         esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
 189 }
 190
 191 static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
 192                                              struct xfrm_state *x,
 193                                              struct ip_esp_hdr *esph,
 194                                              __be32 *seqhi)
 195 {
 196         /* For ESN we move the header forward by 4 bytes to
 197          * accomodate the high bits.  We will move it back after
 198          * encryption.
 199          */
 200         if ((x->props.flags & XFRM_STATE_ESN)) {
 201                 struct xfrm_offload *xo = xfrm_offload(skb);
 202
 203                 esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
 204                 *seqhi = esph->spi;
 205                 if (xo)
 206                         esph->seq_no = htonl(xo->seq.hi);
 207                 else
 208                         esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
 209         }
 210
 211         esph->spi = x->id.spi;
 212
 213         return esph;
 214 }
 215
 216 static void esp_output_done_esn(struct crypto_async_request *base, int err)
 217 {
 218         struct sk_buff *skb = base->data;
 219
 220         esp_output_restore_header(skb);
 221         esp_output_done(base, err);
 222 }
 223
 224 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
 225 {
 226         /* Fill padding... */
 227         if (tfclen) {
 228                 memset(tail, 0, tfclen);
 229                 tail += tfclen;
 230         }
 231         do {
 232                 int i;
 233                 for (i = 0; i < plen - 2; i++)
 234                         tail[i] = i + 1;
 235         } while (0);
 236         tail[plen - 2] = plen - 2;
 237         tail[plen - 1] = proto;
 238 }
 239
 240 int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
 241 {
 242         u8 *tail;
 243         u8 *vaddr;
 244         int nfrags;
 245         struct page *page;
 246         struct sk_buff *trailer;
 247         int tailen = esp->tailen;
 248
 249         if (!skb_cloned(skb)) {
 250                 if (tailen <= skb_tailroom(skb)) {
 251                         nfrags = 1;
 252                         trailer = skb;
 253                         tail = skb_tail_pointer(trailer);
 254
 255                         goto skip_cow;
 256                 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
 257                            && !skb_has_frag_list(skb)) {
 258                         int allocsize;
 259                         struct sock *sk = skb->sk;
 260                         struct page_frag *pfrag = &x->xfrag;
 261
 262                         esp->inplace = false;
 263
 264                         allocsize = ALIGN(tailen, L1_CACHE_BYTES);
 265
 266                         spin_lock_bh(&x->lock);
 267
 268                         if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
 269                                 spin_unlock_bh(&x->lock);
 270                                 goto cow;
 271                         }
 272
 273                         page = pfrag->page;
 274                         get_page(page);
 275
 276                         vaddr = kmap_atomic(page);
 277
 278                         tail = vaddr + pfrag->offset;
 279
 280                         esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
 281
 282                         kunmap_atomic(vaddr);
 283
 284                         nfrags = skb_shinfo(skb)->nr_frags;
 285
 286                         __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
 287                                              tailen);
 288                         skb_shinfo(skb)->nr_frags = ++nfrags;
 289
 290                         pfrag->offset = pfrag->offset + allocsize;
 291
 292                         spin_unlock_bh(&x->lock);
 293
 294                         nfrags++;
 295
 296                         skb->len += tailen;
 297                         skb->data_len += tailen;
 298                         skb->truesize += tailen;
 299                         if (sk)
 300                                 refcount_add(tailen, &sk->sk_wmem_alloc);
 301
 302                         goto out;
 303                 }
 304         }
 305
 306 cow:
 307         nfrags = skb_cow_data(skb, tailen, &trailer);
 308         if (nfrags < 0)
 309                 goto out;
 310         tail = skb_tail_pointer(trailer);
 311
 312 skip_cow:
 313         esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
 314         pskb_put(skb, trailer, tailen);
 315
 316 out:
 317         return nfrags;
 318 }
 319 EXPORT_SYMBOL_GPL(esp6_output_head);
 320
 321 int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
 322 {
 323         u8 *iv;
 324         int alen;
 325         void *tmp;
 326         int ivlen;
 327         int assoclen;
 328         int seqhilen;
 329         __be32 *seqhi;
 330         struct page *page;
 331         struct ip_esp_hdr *esph;
 332         struct aead_request *req;
 333         struct crypto_aead *aead;
 334         struct scatterlist *sg, *dsg;
 335         int err = -ENOMEM;
 336
 337         assoclen = sizeof(struct ip_esp_hdr);
 338         seqhilen = 0;
 339
 340         if (x->props.flags & XFRM_STATE_ESN) {
 341                 seqhilen += sizeof(__be32);
 342                 assoclen += sizeof(__be32);
 343         }
 344
 345         aead = x->data;
 346         alen = crypto_aead_authsize(aead);
 347         ivlen = crypto_aead_ivsize(aead);
 348
 349         tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
 350         if (!tmp)
 351                 goto error;
 352
 353         seqhi = esp_tmp_seqhi(tmp);
 354         iv = esp_tmp_iv(aead, tmp, seqhilen);
 355         req = esp_tmp_req(aead, iv);
 356         sg = esp_req_sg(aead, req);
 357
 358         if (esp->inplace)
 359                 dsg = sg;
 360         else
 361                 dsg = &sg[esp->nfrags];
 362
 363         esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
 364
 365         sg_init_table(sg, esp->nfrags);
 366         err = skb_to_sgvec(skb, sg,
 367                            (unsigned char *)esph - skb->data,
 368                            assoclen + ivlen + esp->clen + alen);
 369         if (unlikely(err < 0))
 370                 goto error_free;
 371
 372         if (!esp->inplace) {
 373                 int allocsize;
 374                 struct page_frag *pfrag = &x->xfrag;
 375
 376                 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
 377
 378                 spin_lock_bh(&x->lock);
 379                 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
 380                         spin_unlock_bh(&x->lock);
 381                         goto error_free;
 382                 }
 383
 384                 skb_shinfo(skb)->nr_frags = 1;
 385
 386                 page = pfrag->page;
 387                 get_page(page);
 388                 /* replace page frags in skb with new page */
 389                 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
 390                 pfrag->offset = pfrag->offset + allocsize;
 391                 spin_unlock_bh(&x->lock);
 392
 393                 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
 394                 err = skb_to_sgvec(skb, dsg,
 395                                    (unsigned char *)esph - skb->data,
 396                                    assoclen + ivlen + esp->clen + alen);
 397                 if (unlikely(err < 0))
 398                         goto error_free;
 399         }
 400
 401         if ((x->props.flags & XFRM_STATE_ESN))
 402                 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
 403         else
 404                 aead_request_set_callback(req, 0, esp_output_done, skb);
 405
 406         aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
 407         aead_request_set_ad(req, assoclen);
 408
 409         memset(iv, 0, ivlen);
 410         memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
 411                min(ivlen, 8));
 412
 413         ESP_SKB_CB(skb)->tmp = tmp;
 414         err = crypto_aead_encrypt(req);
 415
 416         switch (err) {
 417         case -EINPROGRESS:
 418                 goto error;
 419
 420         case -ENOSPC:
 421                 err = NET_XMIT_DROP;
 422                 break;
 423
 424         case 0:
 425                 if ((x->props.flags & XFRM_STATE_ESN))
 426                         esp_output_restore_header(skb);
 427         }
 428
 429         if (sg != dsg)
 430                 esp_ssg_unref(x, tmp);
 431
 432 error_free:
 433         kfree(tmp);
 434 error:
 435         return err;
 436 }
 437 EXPORT_SYMBOL_GPL(esp6_output_tail);
 438
 439 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 440 {
 441         int alen;
 442         int blksize;
 443         struct ip_esp_hdr *esph;
 444         struct crypto_aead *aead;
 445         struct esp_info esp;
 446
 447         esp.inplace = true;
 448
 449         esp.proto = *skb_mac_header(skb);
 450         *skb_mac_header(skb) = IPPROTO_ESP;
 451
 452         /* skb is pure payload to encrypt */
 453
 454         aead = x->data;
 455         alen = crypto_aead_authsize(aead);
 456
 457         esp.tfclen = 0;
 458         if (x->tfcpad) {
 459                 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
 460                 u32 padto;
 461
 462                 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
 463                 if (skb->len < padto)
 464                         esp.tfclen = padto - skb->len;
 465         }
 466         blksize = ALIGN(crypto_aead_blocksize(aead), 4);
 467         esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
 468         esp.plen = esp.clen - skb->len - esp.tfclen;
 469         esp.tailen = esp.tfclen + esp.plen + alen;
 470
 471         esp.nfrags = esp6_output_head(x, skb, &esp);
 472         if (esp.nfrags < 0)
 473                 return esp.nfrags;
 474
 475         esph = ip_esp_hdr(skb);
 476         esph->spi = x->id.spi;
 477
 478         esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
 479         esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
 480                             ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
 481
 482         skb_push(skb, -skb_network_offset(skb));
 483
 484         return esp6_output_tail(x, skb, &esp);
 485 }
 486
 487 static inline int esp_remove_trailer(struct sk_buff *skb)
 488 {
 489         struct xfrm_state *x = xfrm_input_state(skb);
 490         struct xfrm_offload *xo = xfrm_offload(skb);
 491         struct crypto_aead *aead = x->data;
 492         int alen, hlen, elen;
 493         int padlen, trimlen;
 494         __wsum csumdiff;
 495         u8 nexthdr[2];
 496         int ret;
 497
 498         alen = crypto_aead_authsize(aead);
 499         hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
 500         elen = skb->len - hlen;
 501
 502         if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
 503                 ret = xo->proto;
 504                 goto out;
 505         }
 506
 507         ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
 508         BUG_ON(ret);
 509
 510         ret = -EINVAL;
 511         padlen = nexthdr[0];
 512         if (padlen + 2 + alen >= elen) {
 513                 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
 514                                     padlen + 2, elen - alen);
 515                 goto out;
 516         }
 517
 518         trimlen = alen + padlen + 2;
 519         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 520                 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
 521                 skb->csum = csum_block_sub(skb->csum, csumdiff,
 522                                            skb->len - trimlen);
 523         }
 524         pskb_trim(skb, skb->len - trimlen);
 525
 526         ret = nexthdr[1];
 527
 528 out:
 529         return ret;
 530 }
 531
 532 int esp6_input_done2(struct sk_buff *skb, int err)
 533 {
 534         struct xfrm_state *x = xfrm_input_state(skb);
 535         struct xfrm_offload *xo = xfrm_offload(skb);
 536         struct crypto_aead *aead = x->data;
 537         int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
 538         int hdr_len = skb_network_header_len(skb);
 539
 540         if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
 541                 kfree(ESP_SKB_CB(skb)->tmp);
 542
 543         if (unlikely(err))
 544                 goto out;
 545
 546         err = esp_remove_trailer(skb);
 547         if (unlikely(err < 0))
 548                 goto out;
 549
 550         skb_postpull_rcsum(skb, skb_network_header(skb),
 551                            skb_network_header_len(skb));
 552         skb_pull_rcsum(skb, hlen);
 553         if (x->props.mode == XFRM_MODE_TUNNEL)
 554                 skb_reset_transport_header(skb);
 555         else
 556                 skb_set_transport_header(skb, -hdr_len);
 557
 558         /* RFC4303: Drop dummy packets without any error */
 559         if (err == IPPROTO_NONE)
 560                 err = -EINVAL;
 561
 562 out:
 563         return err;
 564 }
 565 EXPORT_SYMBOL_GPL(esp6_input_done2);
 566
 567 static void esp_input_done(struct crypto_async_request *base, int err)
 568 {
 569         struct sk_buff *skb = base->data;
 570
 571         xfrm_input_resume(skb, esp6_input_done2(skb, err));
 572 }
 573
 574 static void esp_input_restore_header(struct sk_buff *skb)
 575 {
 576         esp_restore_header(skb, 0);
 577         __skb_pull(skb, 4);
 578 }
 579
 580 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
 581 {
 582         struct xfrm_state *x = xfrm_input_state(skb);
 583
 584         /* For ESN we move the header forward by 4 bytes to
 585          * accomodate the high bits.  We will move it back after
 586          * decryption.
 587          */
 588         if ((x->props.flags & XFRM_STATE_ESN)) {
 589                 struct ip_esp_hdr *esph = skb_push(skb, 4);
 590
 591                 *seqhi = esph->spi;
 592                 esph->spi = esph->seq_no;
 593                 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
 594         }
 595 }
 596
 597 static void esp_input_done_esn(struct crypto_async_request *base, int err)
 598 {
 599         struct sk_buff *skb = base->data;
 600
 601         esp_input_restore_header(skb);
 602         esp_input_done(base, err);
 603 }
 604
 605 static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
 606 {
 607         struct crypto_aead *aead = x->data;
 608         struct aead_request *req;
 609         struct sk_buff *trailer;
 610         int ivlen = crypto_aead_ivsize(aead);
 611         int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
 612         int nfrags;
 613         int assoclen;
 614         int seqhilen;
 615         int ret = 0;
 616         void *tmp;
 617         __be32 *seqhi;
 618         u8 *iv;
 619         struct scatterlist *sg;
 620
 621         if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) {
 622                 ret = -EINVAL;
 623                 goto out;
 624         }
 625
 626         if (elen <= 0) {
 627                 ret = -EINVAL;
 628                 goto out;
 629         }
 630
 631         assoclen = sizeof(struct ip_esp_hdr);
 632         seqhilen = 0;
 633
 634         if (x->props.flags & XFRM_STATE_ESN) {
 635                 seqhilen += sizeof(__be32);
 636                 assoclen += seqhilen;
 637         }
 638
 639         if (!skb_cloned(skb)) {
 640                 if (!skb_is_nonlinear(skb)) {
 641                         nfrags = 1;
 642
 643                         goto skip_cow;
 644                 } else if (!skb_has_frag_list(skb)) {
 645                         nfrags = skb_shinfo(skb)->nr_frags;
 646                         nfrags++;
 647
 648                         goto skip_cow;
 649                 }
 650         }
 651
 652         nfrags = skb_cow_data(skb, 0, &trailer);
 653         if (nfrags < 0) {
 654                 ret = -EINVAL;
 655                 goto out;
 656         }
 657
 658 skip_cow:
 659         ret = -ENOMEM;
 660         tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
 661         if (!tmp)
 662                 goto out;
 663
 664         ESP_SKB_CB(skb)->tmp = tmp;
 665         seqhi = esp_tmp_seqhi(tmp);
 666         iv = esp_tmp_iv(aead, tmp, seqhilen);
 667         req = esp_tmp_req(aead, iv);
 668         sg = esp_req_sg(aead, req);
 669
 670         esp_input_set_header(skb, seqhi);
 671
 672         sg_init_table(sg, nfrags);
 673         ret = skb_to_sgvec(skb, sg, 0, skb->len);
 674         if (unlikely(ret < 0)) {
 675                 kfree(tmp);
 676                 goto out;
 677         }
 678
 679         skb->ip_summed = CHECKSUM_NONE;
 680
 681         if ((x->props.flags & XFRM_STATE_ESN))
 682                 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
 683         else
 684                 aead_request_set_callback(req, 0, esp_input_done, skb);
 685
 686         aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
 687         aead_request_set_ad(req, assoclen);
 688
 689         ret = crypto_aead_decrypt(req);
 690         if (ret == -EINPROGRESS)
 691                 goto out;
 692
 693         if ((x->props.flags & XFRM_STATE_ESN))
 694                 esp_input_restore_header(skb);
 695
 696         ret = esp6_input_done2(skb, ret);
 697
 698 out:
 699         return ret;
 700 }
 701
 702 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
 703 {
 704         struct crypto_aead *aead = x->data;
 705         u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
 706         unsigned int net_adj;
 707
 708         if (x->props.mode != XFRM_MODE_TUNNEL)
 709                 net_adj = sizeof(struct ipv6hdr);
 710         else
 711                 net_adj = 0;
 712
 713         return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
 714                  net_adj) & ~(blksize - 1)) + net_adj - 2;
 715 }
 716
 717 static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 718                     u8 type, u8 code, int offset, __be32 info)
 719 {
 720         struct net *net = dev_net(skb->dev);
 721         const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
 722         struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
 723         struct xfrm_state *x;
 724
 725         if (type != ICMPV6_PKT_TOOBIG &&
 726             type != NDISC_REDIRECT)
 727                 return 0;
 728
 729         x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
 730                               esph->spi, IPPROTO_ESP, AF_INET6);
 731         if (!x)
 732                 return 0;
 733
 734         if (type == NDISC_REDIRECT)
 735                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
 736                              sock_net_uid(net, NULL));
 737         else
 738                 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
 739         xfrm_state_put(x);
 740
 741         return 0;
 742 }
 743
 744 static void esp6_destroy(struct xfrm_state *x)
 745 {
 746         struct crypto_aead *aead = x->data;
 747
 748         if (!aead)
 749                 return;
 750
 751         crypto_free_aead(aead);
 752 }
 753
 754 static int esp_init_aead(struct xfrm_state *x)
 755 {
 756         char aead_name[CRYPTO_MAX_ALG_NAME];
 757         struct crypto_aead *aead;
 758         int err;
 759
 760         err = -ENAMETOOLONG;
 761         if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
 762                      x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
 763                 goto error;
 764
 765         aead = crypto_alloc_aead(aead_name, 0, 0);
 766         err = PTR_ERR(aead);
 767         if (IS_ERR(aead))
 768                 goto error;
 769
 770         x->data = aead;
 771
 772         err = crypto_aead_setkey(aead, x->aead->alg_key,
 773                                  (x->aead->alg_key_len + 7) / 8);
 774         if (err)
 775                 goto error;
 776
 777         err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
 778         if (err)
 779                 goto error;
 780
 781 error:
 782         return err;
 783 }
 784
 785 static int esp_init_authenc(struct xfrm_state *x)
 786 {
 787         struct crypto_aead *aead;
 788         struct crypto_authenc_key_param *param;
 789         struct rtattr *rta;
 790         char *key;
 791         char *p;
 792         char authenc_name[CRYPTO_MAX_ALG_NAME];
 793         unsigned int keylen;
 794         int err;
 795
 796         err = -EINVAL;
 797         if (!x->ealg)
 798                 goto error;
 799
 800         err = -ENAMETOOLONG;
 801
 802         if ((x->props.flags & XFRM_STATE_ESN)) {
 803                 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
 804                              "%s%sauthencesn(%s,%s)%s",
 805                              x->geniv ?: "", x->geniv ? "(" : "",
 806                              x->aalg ? x->aalg->alg_name : "digest_null",
 807                              x->ealg->alg_name,
 808                              x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
 809                         goto error;
 810         } else {
 811                 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
 812                              "%s%sauthenc(%s,%s)%s",
 813                              x->geniv ?: "", x->geniv ? "(" : "",
 814                              x->aalg ? x->aalg->alg_name : "digest_null",
 815                              x->ealg->alg_name,
 816                              x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
 817                         goto error;
 818         }
 819
 820         aead = crypto_alloc_aead(authenc_name, 0, 0);
 821         err = PTR_ERR(aead);
 822         if (IS_ERR(aead))
 823                 goto error;
 824
 825         x->data = aead;
 826
 827         keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
 828                  (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
 829         err = -ENOMEM;
 830         key = kmalloc(keylen, GFP_KERNEL);
 831         if (!key)
 832                 goto error;
 833
 834         p = key;
 835         rta = (void *)p;
 836         rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
 837         rta->rta_len = RTA_LENGTH(sizeof(*param));
 838         param = RTA_DATA(rta);
 839         p += RTA_SPACE(sizeof(*param));
 840
 841         if (x->aalg) {
 842                 struct xfrm_algo_desc *aalg_desc;
 843
 844                 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
 845                 p += (x->aalg->alg_key_len + 7) / 8;
 846
 847                 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
 848                 BUG_ON(!aalg_desc);
 849
 850                 err = -EINVAL;
 851                 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
 852                     crypto_aead_authsize(aead)) {
 853                         pr_info("ESP: %s digestsize %u != %hu\n",
 854                                 x->aalg->alg_name,
 855                                 crypto_aead_authsize(aead),
 856                                 aalg_desc->uinfo.auth.icv_fullbits / 8);
 857                         goto free_key;
 858                 }
 859
 860                 err = crypto_aead_setauthsize(
 861                         aead, x->aalg->alg_trunc_len / 8);
 862                 if (err)
 863                         goto free_key;
 864         }
 865
 866         param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
 867         memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
 868
 869         err = crypto_aead_setkey(aead, key, keylen);
 870
 871 free_key:
 872         kfree(key);
 873
 874 error:
 875         return err;
 876 }
 877
 878 static int esp6_init_state(struct xfrm_state *x)
 879 {
 880         struct crypto_aead *aead;
 881         u32 align;
 882         int err;
 883
 884         if (x->encap)
 885                 return -EINVAL;
 886
 887         x->data = NULL;
 888
 889         if (x->aead)
 890                 err = esp_init_aead(x);
 891         else
 892                 err = esp_init_authenc(x);
 893
 894         if (err)
 895                 goto error;
 896
 897         aead = x->data;
 898
 899         x->props.header_len = sizeof(struct ip_esp_hdr) +
 900                               crypto_aead_ivsize(aead);
 901         switch (x->props.mode) {
 902         case XFRM_MODE_BEET:
 903                 if (x->sel.family != AF_INET6)
 904                         x->props.header_len += IPV4_BEET_PHMAXLEN +
 905                                                (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
 906                 break;
 907         default:
 908         case XFRM_MODE_TRANSPORT:
 909                 break;
 910         case XFRM_MODE_TUNNEL:
 911                 x->props.header_len += sizeof(struct ipv6hdr);
 912                 break;
 913         }
 914
 915         align = ALIGN(crypto_aead_blocksize(aead), 4);
 916         x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
 917
 918 error:
 919         return err;
 920 }
 921
 922 static int esp6_rcv_cb(struct sk_buff *skb, int err)
 923 {
 924         return 0;
 925 }
 926
 927 static const struct xfrm_type esp6_type = {
 928         .description    = "ESP6",
 929         .owner          = THIS_MODULE,
 930         .proto          = IPPROTO_ESP,
 931         .flags          = XFRM_TYPE_REPLAY_PROT,
 932         .init_state     = esp6_init_state,
 933         .destructor     = esp6_destroy,
 934         .get_mtu        = esp6_get_mtu,
 935         .input          = esp6_input,
 936         .output         = esp6_output,
 937         .hdr_offset     = xfrm6_find_1stfragopt,
 938 };
 939
 940 static struct xfrm6_protocol esp6_protocol = {
 941         .handler        =       xfrm6_rcv,
 942         .cb_handler     =       esp6_rcv_cb,
 943         .err_handler    =       esp6_err,
 944         .priority       =       0,
 945 };
 946
 947 static int __init esp6_init(void)
 948 {
 949         if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
 950                 pr_info("%s: can't add xfrm type\n", __func__);
 951                 return -EAGAIN;
 952         }
 953         if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
 954                 pr_info("%s: can't add protocol\n", __func__);
 955                 xfrm_unregister_type(&esp6_type, AF_INET6);
 956                 return -EAGAIN;
 957         }
 958
 959         return 0;
 960 }
 961
 962 static void __exit esp6_fini(void)
 963 {
 964         if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
 965                 pr_info("%s: can't remove protocol\n", __func__);
 966         if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
 967                 pr_info("%s: can't remove xfrm type\n", __func__);
 968 }
 969
 970 module_init(esp6_init);
 971 module_exit(esp6_fini);
 972
 973 MODULE_LICENSE("GPL");
 974 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);