root/net/ipv6/esp6.c

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DEFINITIONS

This source file includes following definitions.
  1. esp_alloc_tmp
  2. esp_tmp_seqhi
  3. esp_tmp_iv
  4. esp_tmp_req
  5. esp_req_sg
  6. esp_ssg_unref
  7. esp_output_done
  8. esp_restore_header
  9. esp_output_restore_header
  10. esp_output_set_esn
  11. esp_output_done_esn
  12. esp_output_fill_trailer
  13. esp6_output_head
  14. esp6_output_tail
  15. esp6_output
  16. esp_remove_trailer
  17. esp6_input_done2
  18. esp_input_done
  19. esp_input_restore_header
  20. esp_input_set_header
  21. esp_input_done_esn
  22. esp6_input
  23. esp6_err
  24. esp6_destroy
  25. esp_init_aead
  26. esp_init_authenc
  27. esp6_init_state
  28. esp6_rcv_cb
  29. esp6_init
  30. esp6_fini

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

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