linux/net/ipv6/esp6.c
<<
>>
Prefs
   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
  49struct 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
  56static 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 */
  67static 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
  89static inline __be32 *esp_tmp_seqhi(void *tmp)
  90{
  91        return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
  92}
  93
  94static 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
 101static 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
 111static 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
 119static 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
 141static 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                x = skb->sp->xvec[skb->sp->len - 1];
 150        else
 151                x = skb_dst(skb)->xfrm;
 152
 153        tmp = ESP_SKB_CB(skb)->tmp;
 154        esp_ssg_unref(x, tmp);
 155        kfree(tmp);
 156
 157        if (xo && (xo->flags & XFRM_DEV_RESUME)) {
 158                if (err) {
 159                        XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
 160                        kfree_skb(skb);
 161                        return;
 162                }
 163
 164                skb_push(skb, skb->data - skb_mac_header(skb));
 165                secpath_reset(skb);
 166                xfrm_dev_resume(skb);
 167        } else {
 168                xfrm_output_resume(skb, err);
 169        }
 170}
 171
 172/* Move ESP header back into place. */
 173static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
 174{
 175        struct ip_esp_hdr *esph = (void *)(skb->data + offset);
 176        void *tmp = ESP_SKB_CB(skb)->tmp;
 177        __be32 *seqhi = esp_tmp_seqhi(tmp);
 178
 179        esph->seq_no = esph->spi;
 180        esph->spi = *seqhi;
 181}
 182
 183static void esp_output_restore_header(struct sk_buff *skb)
 184{
 185        esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
 186}
 187
 188static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
 189                                             struct xfrm_state *x,
 190                                             struct ip_esp_hdr *esph,
 191                                             __be32 *seqhi)
 192{
 193        /* For ESN we move the header forward by 4 bytes to
 194         * accomodate the high bits.  We will move it back after
 195         * encryption.
 196         */
 197        if ((x->props.flags & XFRM_STATE_ESN)) {
 198                struct xfrm_offload *xo = xfrm_offload(skb);
 199
 200                esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
 201                *seqhi = esph->spi;
 202                if (xo)
 203                        esph->seq_no = htonl(xo->seq.hi);
 204                else
 205                        esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
 206        }
 207
 208        esph->spi = x->id.spi;
 209
 210        return esph;
 211}
 212
 213static void esp_output_done_esn(struct crypto_async_request *base, int err)
 214{
 215        struct sk_buff *skb = base->data;
 216
 217        esp_output_restore_header(skb);
 218        esp_output_done(base, err);
 219}
 220
 221static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
 222{
 223        /* Fill padding... */
 224        if (tfclen) {
 225                memset(tail, 0, tfclen);
 226                tail += tfclen;
 227        }
 228        do {
 229                int i;
 230                for (i = 0; i < plen - 2; i++)
 231                        tail[i] = i + 1;
 232        } while (0);
 233        tail[plen - 2] = plen - 2;
 234        tail[plen - 1] = proto;
 235}
 236
 237int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
 238{
 239        u8 *tail;
 240        u8 *vaddr;
 241        int nfrags;
 242        struct page *page;
 243        struct sk_buff *trailer;
 244        int tailen = esp->tailen;
 245
 246        if (!skb_cloned(skb)) {
 247                if (tailen <= skb_tailroom(skb)) {
 248                        nfrags = 1;
 249                        trailer = skb;
 250                        tail = skb_tail_pointer(trailer);
 251
 252                        goto skip_cow;
 253                } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
 254                           && !skb_has_frag_list(skb)) {
 255                        int allocsize;
 256                        struct sock *sk = skb->sk;
 257                        struct page_frag *pfrag = &x->xfrag;
 258
 259                        esp->inplace = false;
 260
 261                        allocsize = ALIGN(tailen, L1_CACHE_BYTES);
 262
 263                        spin_lock_bh(&x->lock);
 264
 265                        if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
 266                                spin_unlock_bh(&x->lock);
 267                                goto cow;
 268                        }
 269
 270                        page = pfrag->page;
 271                        get_page(page);
 272
 273                        vaddr = kmap_atomic(page);
 274
 275                        tail = vaddr + pfrag->offset;
 276
 277                        esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
 278
 279                        kunmap_atomic(vaddr);
 280
 281                        nfrags = skb_shinfo(skb)->nr_frags;
 282
 283                        __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
 284                                             tailen);
 285                        skb_shinfo(skb)->nr_frags = ++nfrags;
 286
 287                        pfrag->offset = pfrag->offset + allocsize;
 288
 289                        spin_unlock_bh(&x->lock);
 290
 291                        nfrags++;
 292
 293                        skb->len += tailen;
 294                        skb->data_len += tailen;
 295                        skb->truesize += tailen;
 296                        if (sk)
 297                                refcount_add(tailen, &sk->sk_wmem_alloc);
 298
 299                        goto out;
 300                }
 301        }
 302
 303cow:
 304        nfrags = skb_cow_data(skb, tailen, &trailer);
 305        if (nfrags < 0)
 306                goto out;
 307        tail = skb_tail_pointer(trailer);
 308
 309skip_cow:
 310        esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
 311        pskb_put(skb, trailer, tailen);
 312
 313out:
 314        return nfrags;
 315}
 316EXPORT_SYMBOL_GPL(esp6_output_head);
 317
 318int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
 319{
 320        u8 *iv;
 321        int alen;
 322        void *tmp;
 323        int ivlen;
 324        int assoclen;
 325        int seqhilen;
 326        __be32 *seqhi;
 327        struct page *page;
 328        struct ip_esp_hdr *esph;
 329        struct aead_request *req;
 330        struct crypto_aead *aead;
 331        struct scatterlist *sg, *dsg;
 332        int err = -ENOMEM;
 333
 334        assoclen = sizeof(struct ip_esp_hdr);
 335        seqhilen = 0;
 336
 337        if (x->props.flags & XFRM_STATE_ESN) {
 338                seqhilen += sizeof(__be32);
 339                assoclen += sizeof(__be32);
 340        }
 341
 342        aead = x->data;
 343        alen = crypto_aead_authsize(aead);
 344        ivlen = crypto_aead_ivsize(aead);
 345
 346        tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
 347        if (!tmp)
 348                goto error;
 349
 350        seqhi = esp_tmp_seqhi(tmp);
 351        iv = esp_tmp_iv(aead, tmp, seqhilen);
 352        req = esp_tmp_req(aead, iv);
 353        sg = esp_req_sg(aead, req);
 354
 355        if (esp->inplace)
 356                dsg = sg;
 357        else
 358                dsg = &sg[esp->nfrags];
 359
 360        esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
 361
 362        sg_init_table(sg, esp->nfrags);
 363        err = skb_to_sgvec(skb, sg,
 364                           (unsigned char *)esph - skb->data,
 365                           assoclen + ivlen + esp->clen + alen);
 366        if (unlikely(err < 0))
 367                goto error_free;
 368
 369        if (!esp->inplace) {
 370                int allocsize;
 371                struct page_frag *pfrag = &x->xfrag;
 372
 373                allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
 374
 375                spin_lock_bh(&x->lock);
 376                if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
 377                        spin_unlock_bh(&x->lock);
 378                        goto error_free;
 379                }
 380
 381                skb_shinfo(skb)->nr_frags = 1;
 382
 383                page = pfrag->page;
 384                get_page(page);
 385                /* replace page frags in skb with new page */
 386                __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
 387                pfrag->offset = pfrag->offset + allocsize;
 388                spin_unlock_bh(&x->lock);
 389
 390                sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
 391                err = skb_to_sgvec(skb, dsg,
 392                                   (unsigned char *)esph - skb->data,
 393                                   assoclen + ivlen + esp->clen + alen);
 394                if (unlikely(err < 0))
 395                        goto error_free;
 396        }
 397
 398        if ((x->props.flags & XFRM_STATE_ESN))
 399                aead_request_set_callback(req, 0, esp_output_done_esn, skb);
 400        else
 401                aead_request_set_callback(req, 0, esp_output_done, skb);
 402
 403        aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
 404        aead_request_set_ad(req, assoclen);
 405
 406        memset(iv, 0, ivlen);
 407        memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
 408               min(ivlen, 8));
 409
 410        ESP_SKB_CB(skb)->tmp = tmp;
 411        err = crypto_aead_encrypt(req);
 412
 413        switch (err) {
 414        case -EINPROGRESS:
 415                goto error;
 416
 417        case -ENOSPC:
 418                err = NET_XMIT_DROP;
 419                break;
 420
 421        case 0:
 422                if ((x->props.flags & XFRM_STATE_ESN))
 423                        esp_output_restore_header(skb);
 424        }
 425
 426        if (sg != dsg)
 427                esp_ssg_unref(x, tmp);
 428
 429error_free:
 430        kfree(tmp);
 431error:
 432        return err;
 433}
 434EXPORT_SYMBOL_GPL(esp6_output_tail);
 435
 436static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 437{
 438        int alen;
 439        int blksize;
 440        struct ip_esp_hdr *esph;
 441        struct crypto_aead *aead;
 442        struct esp_info esp;
 443
 444        esp.inplace = true;
 445
 446        esp.proto = *skb_mac_header(skb);
 447        *skb_mac_header(skb) = IPPROTO_ESP;
 448
 449        /* skb is pure payload to encrypt */
 450
 451        aead = x->data;
 452        alen = crypto_aead_authsize(aead);
 453
 454        esp.tfclen = 0;
 455        if (x->tfcpad) {
 456                struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
 457                u32 padto;
 458
 459                padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
 460                if (skb->len < padto)
 461                        esp.tfclen = padto - skb->len;
 462        }
 463        blksize = ALIGN(crypto_aead_blocksize(aead), 4);
 464        esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
 465        esp.plen = esp.clen - skb->len - esp.tfclen;
 466        esp.tailen = esp.tfclen + esp.plen + alen;
 467
 468        esp.nfrags = esp6_output_head(x, skb, &esp);
 469        if (esp.nfrags < 0)
 470                return esp.nfrags;
 471
 472        esph = ip_esp_hdr(skb);
 473        esph->spi = x->id.spi;
 474
 475        esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
 476        esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
 477                            ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
 478
 479        skb_push(skb, -skb_network_offset(skb));
 480
 481        return esp6_output_tail(x, skb, &esp);
 482}
 483
 484static inline int esp_remove_trailer(struct sk_buff *skb)
 485{
 486        struct xfrm_state *x = xfrm_input_state(skb);
 487        struct xfrm_offload *xo = xfrm_offload(skb);
 488        struct crypto_aead *aead = x->data;
 489        int alen, hlen, elen;
 490        int padlen, trimlen;
 491        __wsum csumdiff;
 492        u8 nexthdr[2];
 493        int ret;
 494
 495        alen = crypto_aead_authsize(aead);
 496        hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
 497        elen = skb->len - hlen;
 498
 499        if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
 500                ret = xo->proto;
 501                goto out;
 502        }
 503
 504        ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
 505        BUG_ON(ret);
 506
 507        ret = -EINVAL;
 508        padlen = nexthdr[0];
 509        if (padlen + 2 + alen >= elen) {
 510                net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
 511                                    padlen + 2, elen - alen);
 512                goto out;
 513        }
 514
 515        trimlen = alen + padlen + 2;
 516        if (skb->ip_summed == CHECKSUM_COMPLETE) {
 517                csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
 518                skb->csum = csum_block_sub(skb->csum, csumdiff,
 519                                           skb->len - trimlen);
 520        }
 521        pskb_trim(skb, skb->len - trimlen);
 522
 523        ret = nexthdr[1];
 524
 525out:
 526        return ret;
 527}
 528
 529int esp6_input_done2(struct sk_buff *skb, int err)
 530{
 531        struct xfrm_state *x = xfrm_input_state(skb);
 532        struct xfrm_offload *xo = xfrm_offload(skb);
 533        struct crypto_aead *aead = x->data;
 534        int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
 535        int hdr_len = skb_network_header_len(skb);
 536
 537        if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
 538                kfree(ESP_SKB_CB(skb)->tmp);
 539
 540        if (unlikely(err))
 541                goto out;
 542
 543        err = esp_remove_trailer(skb);
 544        if (unlikely(err < 0))
 545                goto out;
 546
 547        skb_postpull_rcsum(skb, skb_network_header(skb),
 548                           skb_network_header_len(skb));
 549        skb_pull_rcsum(skb, hlen);
 550        if (x->props.mode == XFRM_MODE_TUNNEL)
 551                skb_reset_transport_header(skb);
 552        else
 553                skb_set_transport_header(skb, -hdr_len);
 554
 555        /* RFC4303: Drop dummy packets without any error */
 556        if (err == IPPROTO_NONE)
 557                err = -EINVAL;
 558
 559out:
 560        return err;
 561}
 562EXPORT_SYMBOL_GPL(esp6_input_done2);
 563
 564static void esp_input_done(struct crypto_async_request *base, int err)
 565{
 566        struct sk_buff *skb = base->data;
 567
 568        xfrm_input_resume(skb, esp6_input_done2(skb, err));
 569}
 570
 571static void esp_input_restore_header(struct sk_buff *skb)
 572{
 573        esp_restore_header(skb, 0);
 574        __skb_pull(skb, 4);
 575}
 576
 577static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
 578{
 579        struct xfrm_state *x = xfrm_input_state(skb);
 580
 581        /* For ESN we move the header forward by 4 bytes to
 582         * accomodate the high bits.  We will move it back after
 583         * decryption.
 584         */
 585        if ((x->props.flags & XFRM_STATE_ESN)) {
 586                struct ip_esp_hdr *esph = skb_push(skb, 4);
 587
 588                *seqhi = esph->spi;
 589                esph->spi = esph->seq_no;
 590                esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
 591        }
 592}
 593
 594static void esp_input_done_esn(struct crypto_async_request *base, int err)
 595{
 596        struct sk_buff *skb = base->data;
 597
 598        esp_input_restore_header(skb);
 599        esp_input_done(base, err);
 600}
 601
 602static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
 603{
 604        struct ip_esp_hdr *esph;
 605        struct crypto_aead *aead = x->data;
 606        struct aead_request *req;
 607        struct sk_buff *trailer;
 608        int ivlen = crypto_aead_ivsize(aead);
 609        int elen = skb->len - sizeof(*esph) - ivlen;
 610        int nfrags;
 611        int assoclen;
 612        int seqhilen;
 613        int ret = 0;
 614        void *tmp;
 615        __be32 *seqhi;
 616        u8 *iv;
 617        struct scatterlist *sg;
 618
 619        if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) {
 620                ret = -EINVAL;
 621                goto out;
 622        }
 623
 624        if (elen <= 0) {
 625                ret = -EINVAL;
 626                goto out;
 627        }
 628
 629        assoclen = sizeof(*esph);
 630        seqhilen = 0;
 631
 632        if (x->props.flags & XFRM_STATE_ESN) {
 633                seqhilen += sizeof(__be32);
 634                assoclen += seqhilen;
 635        }
 636
 637        if (!skb_cloned(skb)) {
 638                if (!skb_is_nonlinear(skb)) {
 639                        nfrags = 1;
 640
 641                        goto skip_cow;
 642                } else if (!skb_has_frag_list(skb)) {
 643                        nfrags = skb_shinfo(skb)->nr_frags;
 644                        nfrags++;
 645
 646                        goto skip_cow;
 647                }
 648        }
 649
 650        nfrags = skb_cow_data(skb, 0, &trailer);
 651        if (nfrags < 0) {
 652                ret = -EINVAL;
 653                goto out;
 654        }
 655
 656skip_cow:
 657        ret = -ENOMEM;
 658        tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
 659        if (!tmp)
 660                goto out;
 661
 662        ESP_SKB_CB(skb)->tmp = tmp;
 663        seqhi = esp_tmp_seqhi(tmp);
 664        iv = esp_tmp_iv(aead, tmp, seqhilen);
 665        req = esp_tmp_req(aead, iv);
 666        sg = esp_req_sg(aead, req);
 667
 668        esp_input_set_header(skb, seqhi);
 669
 670        sg_init_table(sg, nfrags);
 671        ret = skb_to_sgvec(skb, sg, 0, skb->len);
 672        if (unlikely(ret < 0))
 673                goto out;
 674
 675        skb->ip_summed = CHECKSUM_NONE;
 676
 677        if ((x->props.flags & XFRM_STATE_ESN))
 678                aead_request_set_callback(req, 0, esp_input_done_esn, skb);
 679        else
 680                aead_request_set_callback(req, 0, esp_input_done, skb);
 681
 682        aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
 683        aead_request_set_ad(req, assoclen);
 684
 685        ret = crypto_aead_decrypt(req);
 686        if (ret == -EINPROGRESS)
 687                goto out;
 688
 689        if ((x->props.flags & XFRM_STATE_ESN))
 690                esp_input_restore_header(skb);
 691
 692        ret = esp6_input_done2(skb, ret);
 693
 694out:
 695        return ret;
 696}
 697
 698static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
 699{
 700        struct crypto_aead *aead = x->data;
 701        u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
 702        unsigned int net_adj;
 703
 704        if (x->props.mode != XFRM_MODE_TUNNEL)
 705                net_adj = sizeof(struct ipv6hdr);
 706        else
 707                net_adj = 0;
 708
 709        return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
 710                 net_adj) & ~(blksize - 1)) + net_adj - 2;
 711}
 712
 713static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 714                    u8 type, u8 code, int offset, __be32 info)
 715{
 716        struct net *net = dev_net(skb->dev);
 717        const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
 718        struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
 719        struct xfrm_state *x;
 720
 721        if (type != ICMPV6_PKT_TOOBIG &&
 722            type != NDISC_REDIRECT)
 723                return 0;
 724
 725        x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
 726                              esph->spi, IPPROTO_ESP, AF_INET6);
 727        if (!x)
 728                return 0;
 729
 730        if (type == NDISC_REDIRECT)
 731                ip6_redirect(skb, net, skb->dev->ifindex, 0,
 732                             sock_net_uid(net, NULL));
 733        else
 734                ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
 735        xfrm_state_put(x);
 736
 737        return 0;
 738}
 739
 740static void esp6_destroy(struct xfrm_state *x)
 741{
 742        struct crypto_aead *aead = x->data;
 743
 744        if (!aead)
 745                return;
 746
 747        crypto_free_aead(aead);
 748}
 749
 750static int esp_init_aead(struct xfrm_state *x)
 751{
 752        char aead_name[CRYPTO_MAX_ALG_NAME];
 753        struct crypto_aead *aead;
 754        int err;
 755
 756        err = -ENAMETOOLONG;
 757        if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
 758                     x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
 759                goto error;
 760
 761        aead = crypto_alloc_aead(aead_name, 0, 0);
 762        err = PTR_ERR(aead);
 763        if (IS_ERR(aead))
 764                goto error;
 765
 766        x->data = aead;
 767
 768        err = crypto_aead_setkey(aead, x->aead->alg_key,
 769                                 (x->aead->alg_key_len + 7) / 8);
 770        if (err)
 771                goto error;
 772
 773        err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
 774        if (err)
 775                goto error;
 776
 777error:
 778        return err;
 779}
 780
 781static int esp_init_authenc(struct xfrm_state *x)
 782{
 783        struct crypto_aead *aead;
 784        struct crypto_authenc_key_param *param;
 785        struct rtattr *rta;
 786        char *key;
 787        char *p;
 788        char authenc_name[CRYPTO_MAX_ALG_NAME];
 789        unsigned int keylen;
 790        int err;
 791
 792        err = -EINVAL;
 793        if (!x->ealg)
 794                goto error;
 795
 796        err = -ENAMETOOLONG;
 797
 798        if ((x->props.flags & XFRM_STATE_ESN)) {
 799                if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
 800                             "%s%sauthencesn(%s,%s)%s",
 801                             x->geniv ?: "", x->geniv ? "(" : "",
 802                             x->aalg ? x->aalg->alg_name : "digest_null",
 803                             x->ealg->alg_name,
 804                             x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
 805                        goto error;
 806        } else {
 807                if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
 808                             "%s%sauthenc(%s,%s)%s",
 809                             x->geniv ?: "", x->geniv ? "(" : "",
 810                             x->aalg ? x->aalg->alg_name : "digest_null",
 811                             x->ealg->alg_name,
 812                             x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
 813                        goto error;
 814        }
 815
 816        aead = crypto_alloc_aead(authenc_name, 0, 0);
 817        err = PTR_ERR(aead);
 818        if (IS_ERR(aead))
 819                goto error;
 820
 821        x->data = aead;
 822
 823        keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
 824                 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
 825        err = -ENOMEM;
 826        key = kmalloc(keylen, GFP_KERNEL);
 827        if (!key)
 828                goto error;
 829
 830        p = key;
 831        rta = (void *)p;
 832        rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
 833        rta->rta_len = RTA_LENGTH(sizeof(*param));
 834        param = RTA_DATA(rta);
 835        p += RTA_SPACE(sizeof(*param));
 836
 837        if (x->aalg) {
 838                struct xfrm_algo_desc *aalg_desc;
 839
 840                memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
 841                p += (x->aalg->alg_key_len + 7) / 8;
 842
 843                aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
 844                BUG_ON(!aalg_desc);
 845
 846                err = -EINVAL;
 847                if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
 848                    crypto_aead_authsize(aead)) {
 849                        pr_info("ESP: %s digestsize %u != %hu\n",
 850                                x->aalg->alg_name,
 851                                crypto_aead_authsize(aead),
 852                                aalg_desc->uinfo.auth.icv_fullbits / 8);
 853                        goto free_key;
 854                }
 855
 856                err = crypto_aead_setauthsize(
 857                        aead, x->aalg->alg_trunc_len / 8);
 858                if (err)
 859                        goto free_key;
 860        }
 861
 862        param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
 863        memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
 864
 865        err = crypto_aead_setkey(aead, key, keylen);
 866
 867free_key:
 868        kfree(key);
 869
 870error:
 871        return err;
 872}
 873
 874static int esp6_init_state(struct xfrm_state *x)
 875{
 876        struct crypto_aead *aead;
 877        u32 align;
 878        int err;
 879
 880        if (x->encap)
 881                return -EINVAL;
 882
 883        x->data = NULL;
 884
 885        if (x->aead)
 886                err = esp_init_aead(x);
 887        else
 888                err = esp_init_authenc(x);
 889
 890        if (err)
 891                goto error;
 892
 893        aead = x->data;
 894
 895        x->props.header_len = sizeof(struct ip_esp_hdr) +
 896                              crypto_aead_ivsize(aead);
 897        switch (x->props.mode) {
 898        case XFRM_MODE_BEET:
 899                if (x->sel.family != AF_INET6)
 900                        x->props.header_len += IPV4_BEET_PHMAXLEN +
 901                                               (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
 902                break;
 903        default:
 904        case XFRM_MODE_TRANSPORT:
 905                break;
 906        case XFRM_MODE_TUNNEL:
 907                x->props.header_len += sizeof(struct ipv6hdr);
 908                break;
 909        }
 910
 911        align = ALIGN(crypto_aead_blocksize(aead), 4);
 912        x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
 913
 914error:
 915        return err;
 916}
 917
 918static int esp6_rcv_cb(struct sk_buff *skb, int err)
 919{
 920        return 0;
 921}
 922
 923static const struct xfrm_type esp6_type = {
 924        .description    = "ESP6",
 925        .owner          = THIS_MODULE,
 926        .proto          = IPPROTO_ESP,
 927        .flags          = XFRM_TYPE_REPLAY_PROT,
 928        .init_state     = esp6_init_state,
 929        .destructor     = esp6_destroy,
 930        .get_mtu        = esp6_get_mtu,
 931        .input          = esp6_input,
 932        .output         = esp6_output,
 933        .hdr_offset     = xfrm6_find_1stfragopt,
 934};
 935
 936static struct xfrm6_protocol esp6_protocol = {
 937        .handler        =       xfrm6_rcv,
 938        .cb_handler     =       esp6_rcv_cb,
 939        .err_handler    =       esp6_err,
 940        .priority       =       0,
 941};
 942
 943static int __init esp6_init(void)
 944{
 945        if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
 946                pr_info("%s: can't add xfrm type\n", __func__);
 947                return -EAGAIN;
 948        }
 949        if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
 950                pr_info("%s: can't add protocol\n", __func__);
 951                xfrm_unregister_type(&esp6_type, AF_INET6);
 952                return -EAGAIN;
 953        }
 954
 955        return 0;
 956}
 957
 958static void __exit esp6_fini(void)
 959{
 960        if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
 961                pr_info("%s: can't remove protocol\n", __func__);
 962        if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
 963                pr_info("%s: can't remove xfrm type\n", __func__);
 964}
 965
 966module_init(esp6_init);
 967module_exit(esp6_fini);
 968
 969MODULE_LICENSE("GPL");
 970MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
 971