linux/net/ipv4/esp4.c
<<
>>
Prefs
   1#define pr_fmt(fmt) "IPsec: " fmt
   2
   3#include <crypto/aead.h>
   4#include <crypto/authenc.h>
   5#include <linux/err.h>
   6#include <linux/module.h>
   7#include <net/ip.h>
   8#include <net/xfrm.h>
   9#include <net/esp.h>
  10#include <linux/scatterlist.h>
  11#include <linux/kernel.h>
  12#include <linux/pfkeyv2.h>
  13#include <linux/rtnetlink.h>
  14#include <linux/slab.h>
  15#include <linux/spinlock.h>
  16#include <linux/in6.h>
  17#include <net/icmp.h>
  18#include <net/protocol.h>
  19#include <net/udp.h>
  20
  21struct esp_skb_cb {
  22        struct xfrm_skb_cb xfrm;
  23        void *tmp;
  24};
  25
  26#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
  27
  28static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
  29
  30/*
  31 * Allocate an AEAD request structure with extra space for SG and IV.
  32 *
  33 * For alignment considerations the IV is placed at the front, followed
  34 * by the request and finally the SG list.
  35 *
  36 * TODO: Use spare space in skb for this where possible.
  37 */
  38static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqhilen)
  39{
  40        unsigned int len;
  41
  42        len = seqhilen;
  43
  44        len += crypto_aead_ivsize(aead);
  45
  46        if (len) {
  47                len += crypto_aead_alignmask(aead) &
  48                       ~(crypto_tfm_ctx_alignment() - 1);
  49                len = ALIGN(len, crypto_tfm_ctx_alignment());
  50        }
  51
  52        len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
  53        len = ALIGN(len, __alignof__(struct scatterlist));
  54
  55        len += sizeof(struct scatterlist) * nfrags;
  56
  57        return kmalloc(len, GFP_ATOMIC);
  58}
  59
  60static inline __be32 *esp_tmp_seqhi(void *tmp)
  61{
  62        return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
  63}
  64static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
  65{
  66        return crypto_aead_ivsize(aead) ?
  67               PTR_ALIGN((u8 *)tmp + seqhilen,
  68                         crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
  69}
  70
  71static inline struct aead_givcrypt_request *esp_tmp_givreq(
  72        struct crypto_aead *aead, u8 *iv)
  73{
  74        struct aead_givcrypt_request *req;
  75
  76        req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
  77                                crypto_tfm_ctx_alignment());
  78        aead_givcrypt_set_tfm(req, aead);
  79        return req;
  80}
  81
  82static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
  83{
  84        struct aead_request *req;
  85
  86        req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
  87                                crypto_tfm_ctx_alignment());
  88        aead_request_set_tfm(req, aead);
  89        return req;
  90}
  91
  92static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
  93                                             struct aead_request *req)
  94{
  95        return (void *)ALIGN((unsigned long)(req + 1) +
  96                             crypto_aead_reqsize(aead),
  97                             __alignof__(struct scatterlist));
  98}
  99
 100static inline struct scatterlist *esp_givreq_sg(
 101        struct crypto_aead *aead, struct aead_givcrypt_request *req)
 102{
 103        return (void *)ALIGN((unsigned long)(req + 1) +
 104                             crypto_aead_reqsize(aead),
 105                             __alignof__(struct scatterlist));
 106}
 107
 108static void esp_output_done(struct crypto_async_request *base, int err)
 109{
 110        struct sk_buff *skb = base->data;
 111
 112        kfree(ESP_SKB_CB(skb)->tmp);
 113        xfrm_output_resume(skb, err);
 114}
 115
 116static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
 117{
 118        int err;
 119        struct ip_esp_hdr *esph;
 120        struct crypto_aead *aead;
 121        struct aead_givcrypt_request *req;
 122        struct scatterlist *sg;
 123        struct scatterlist *asg;
 124        struct esp_data *esp;
 125        struct sk_buff *trailer;
 126        void *tmp;
 127        u8 *iv;
 128        u8 *tail;
 129        int blksize;
 130        int clen;
 131        int alen;
 132        int plen;
 133        int tfclen;
 134        int nfrags;
 135        int assoclen;
 136        int sglists;
 137        int seqhilen;
 138        __be32 *seqhi;
 139
 140        /* skb is pure payload to encrypt */
 141
 142        err = -ENOMEM;
 143
 144        esp = x->data;
 145        aead = esp->aead;
 146        alen = crypto_aead_authsize(aead);
 147
 148        tfclen = 0;
 149        if (x->tfcpad) {
 150                struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
 151                u32 padto;
 152
 153                padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
 154                if (skb->len < padto)
 155                        tfclen = padto - skb->len;
 156        }
 157        blksize = ALIGN(crypto_aead_blocksize(aead), 4);
 158        clen = ALIGN(skb->len + 2 + tfclen, blksize);
 159        if (esp->padlen)
 160                clen = ALIGN(clen, esp->padlen);
 161        plen = clen - skb->len - tfclen;
 162
 163        err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
 164        if (err < 0)
 165                goto error;
 166        nfrags = err;
 167
 168        assoclen = sizeof(*esph);
 169        sglists = 1;
 170        seqhilen = 0;
 171
 172        if (x->props.flags & XFRM_STATE_ESN) {
 173                sglists += 2;
 174                seqhilen += sizeof(__be32);
 175                assoclen += seqhilen;
 176        }
 177
 178        tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
 179        if (!tmp)
 180                goto error;
 181
 182        seqhi = esp_tmp_seqhi(tmp);
 183        iv = esp_tmp_iv(aead, tmp, seqhilen);
 184        req = esp_tmp_givreq(aead, iv);
 185        asg = esp_givreq_sg(aead, req);
 186        sg = asg + sglists;
 187
 188        /* Fill padding... */
 189        tail = skb_tail_pointer(trailer);
 190        if (tfclen) {
 191                memset(tail, 0, tfclen);
 192                tail += tfclen;
 193        }
 194        do {
 195                int i;
 196                for (i = 0; i < plen - 2; i++)
 197                        tail[i] = i + 1;
 198        } while (0);
 199        tail[plen - 2] = plen - 2;
 200        tail[plen - 1] = *skb_mac_header(skb);
 201        pskb_put(skb, trailer, clen - skb->len + alen);
 202
 203        skb_push(skb, -skb_network_offset(skb));
 204        esph = ip_esp_hdr(skb);
 205        *skb_mac_header(skb) = IPPROTO_ESP;
 206
 207        /* this is non-NULL only with UDP Encapsulation */
 208        if (x->encap) {
 209                struct xfrm_encap_tmpl *encap = x->encap;
 210                struct udphdr *uh;
 211                __be32 *udpdata32;
 212                __be16 sport, dport;
 213                int encap_type;
 214
 215                spin_lock_bh(&x->lock);
 216                sport = encap->encap_sport;
 217                dport = encap->encap_dport;
 218                encap_type = encap->encap_type;
 219                spin_unlock_bh(&x->lock);
 220
 221                uh = (struct udphdr *)esph;
 222                uh->source = sport;
 223                uh->dest = dport;
 224                uh->len = htons(skb->len - skb_transport_offset(skb));
 225                uh->check = 0;
 226
 227                switch (encap_type) {
 228                default:
 229                case UDP_ENCAP_ESPINUDP:
 230                        esph = (struct ip_esp_hdr *)(uh + 1);
 231                        break;
 232                case UDP_ENCAP_ESPINUDP_NON_IKE:
 233                        udpdata32 = (__be32 *)(uh + 1);
 234                        udpdata32[0] = udpdata32[1] = 0;
 235                        esph = (struct ip_esp_hdr *)(udpdata32 + 2);
 236                        break;
 237                }
 238
 239                *skb_mac_header(skb) = IPPROTO_UDP;
 240        }
 241
 242        esph->spi = x->id.spi;
 243        esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
 244
 245        sg_init_table(sg, nfrags);
 246        skb_to_sgvec(skb, sg,
 247                     esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
 248                     clen + alen);
 249
 250        if ((x->props.flags & XFRM_STATE_ESN)) {
 251                sg_init_table(asg, 3);
 252                sg_set_buf(asg, &esph->spi, sizeof(__be32));
 253                *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
 254                sg_set_buf(asg + 1, seqhi, seqhilen);
 255                sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
 256        } else
 257                sg_init_one(asg, esph, sizeof(*esph));
 258
 259        aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
 260        aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
 261        aead_givcrypt_set_assoc(req, asg, assoclen);
 262        aead_givcrypt_set_giv(req, esph->enc_data,
 263                              XFRM_SKB_CB(skb)->seq.output.low);
 264
 265        ESP_SKB_CB(skb)->tmp = tmp;
 266        err = crypto_aead_givencrypt(req);
 267        if (err == -EINPROGRESS)
 268                goto error;
 269
 270        if (err == -EBUSY)
 271                err = NET_XMIT_DROP;
 272
 273        kfree(tmp);
 274
 275error:
 276        return err;
 277}
 278
 279static int esp_input_done2(struct sk_buff *skb, int err)
 280{
 281        const struct iphdr *iph;
 282        struct xfrm_state *x = xfrm_input_state(skb);
 283        struct esp_data *esp = x->data;
 284        struct crypto_aead *aead = esp->aead;
 285        int alen = crypto_aead_authsize(aead);
 286        int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
 287        int elen = skb->len - hlen;
 288        int ihl;
 289        u8 nexthdr[2];
 290        int padlen;
 291
 292        kfree(ESP_SKB_CB(skb)->tmp);
 293
 294        if (unlikely(err))
 295                goto out;
 296
 297        if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
 298                BUG();
 299
 300        err = -EINVAL;
 301        padlen = nexthdr[0];
 302        if (padlen + 2 + alen >= elen)
 303                goto out;
 304
 305        /* ... check padding bits here. Silly. :-) */
 306
 307        iph = ip_hdr(skb);
 308        ihl = iph->ihl * 4;
 309
 310        if (x->encap) {
 311                struct xfrm_encap_tmpl *encap = x->encap;
 312                struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
 313
 314                /*
 315                 * 1) if the NAT-T peer's IP or port changed then
 316                 *    advertize the change to the keying daemon.
 317                 *    This is an inbound SA, so just compare
 318                 *    SRC ports.
 319                 */
 320                if (iph->saddr != x->props.saddr.a4 ||
 321                    uh->source != encap->encap_sport) {
 322                        xfrm_address_t ipaddr;
 323
 324                        ipaddr.a4 = iph->saddr;
 325                        km_new_mapping(x, &ipaddr, uh->source);
 326
 327                        /* XXX: perhaps add an extra
 328                         * policy check here, to see
 329                         * if we should allow or
 330                         * reject a packet from a
 331                         * different source
 332                         * address/port.
 333                         */
 334                }
 335
 336                /*
 337                 * 2) ignore UDP/TCP checksums in case
 338                 *    of NAT-T in Transport Mode, or
 339                 *    perform other post-processing fixes
 340                 *    as per draft-ietf-ipsec-udp-encaps-06,
 341                 *    section 3.1.2
 342                 */
 343                if (x->props.mode == XFRM_MODE_TRANSPORT)
 344                        skb->ip_summed = CHECKSUM_UNNECESSARY;
 345        }
 346
 347        pskb_trim(skb, skb->len - alen - padlen - 2);
 348        __skb_pull(skb, hlen);
 349        skb_set_transport_header(skb, -ihl);
 350
 351        err = nexthdr[1];
 352
 353        /* RFC4303: Drop dummy packets without any error */
 354        if (err == IPPROTO_NONE)
 355                err = -EINVAL;
 356
 357out:
 358        return err;
 359}
 360
 361static void esp_input_done(struct crypto_async_request *base, int err)
 362{
 363        struct sk_buff *skb = base->data;
 364
 365        xfrm_input_resume(skb, esp_input_done2(skb, err));
 366}
 367
 368/*
 369 * Note: detecting truncated vs. non-truncated authentication data is very
 370 * expensive, so we only support truncated data, which is the recommended
 371 * and common case.
 372 */
 373static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 374{
 375        struct ip_esp_hdr *esph;
 376        struct esp_data *esp = x->data;
 377        struct crypto_aead *aead = esp->aead;
 378        struct aead_request *req;
 379        struct sk_buff *trailer;
 380        int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
 381        int nfrags;
 382        int assoclen;
 383        int sglists;
 384        int seqhilen;
 385        __be32 *seqhi;
 386        void *tmp;
 387        u8 *iv;
 388        struct scatterlist *sg;
 389        struct scatterlist *asg;
 390        int err = -EINVAL;
 391
 392        if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
 393                goto out;
 394
 395        if (elen <= 0)
 396                goto out;
 397
 398        if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
 399                goto out;
 400        nfrags = err;
 401
 402        assoclen = sizeof(*esph);
 403        sglists = 1;
 404        seqhilen = 0;
 405
 406        if (x->props.flags & XFRM_STATE_ESN) {
 407                sglists += 2;
 408                seqhilen += sizeof(__be32);
 409                assoclen += seqhilen;
 410        }
 411
 412        err = -ENOMEM;
 413        tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
 414        if (!tmp)
 415                goto out;
 416
 417        ESP_SKB_CB(skb)->tmp = tmp;
 418        seqhi = esp_tmp_seqhi(tmp);
 419        iv = esp_tmp_iv(aead, tmp, seqhilen);
 420        req = esp_tmp_req(aead, iv);
 421        asg = esp_req_sg(aead, req);
 422        sg = asg + sglists;
 423
 424        skb->ip_summed = CHECKSUM_NONE;
 425
 426        esph = (struct ip_esp_hdr *)skb->data;
 427
 428        /* Get ivec. This can be wrong, check against another impls. */
 429        iv = esph->enc_data;
 430
 431        sg_init_table(sg, nfrags);
 432        skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
 433
 434        if ((x->props.flags & XFRM_STATE_ESN)) {
 435                sg_init_table(asg, 3);
 436                sg_set_buf(asg, &esph->spi, sizeof(__be32));
 437                *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
 438                sg_set_buf(asg + 1, seqhi, seqhilen);
 439                sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
 440        } else
 441                sg_init_one(asg, esph, sizeof(*esph));
 442
 443        aead_request_set_callback(req, 0, esp_input_done, skb);
 444        aead_request_set_crypt(req, sg, sg, elen, iv);
 445        aead_request_set_assoc(req, asg, assoclen);
 446
 447        err = crypto_aead_decrypt(req);
 448        if (err == -EINPROGRESS)
 449                goto out;
 450
 451        err = esp_input_done2(skb, err);
 452
 453out:
 454        return err;
 455}
 456
 457static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
 458{
 459        struct esp_data *esp = x->data;
 460        u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
 461        u32 align = max_t(u32, blksize, esp->padlen);
 462        unsigned int net_adj;
 463
 464        switch (x->props.mode) {
 465        case XFRM_MODE_TRANSPORT:
 466        case XFRM_MODE_BEET:
 467                net_adj = sizeof(struct iphdr);
 468                break;
 469        case XFRM_MODE_TUNNEL:
 470                net_adj = 0;
 471                break;
 472        default:
 473                BUG();
 474        }
 475
 476        return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) -
 477                 net_adj) & ~(align - 1)) + (net_adj - 2);
 478}
 479
 480static void esp4_err(struct sk_buff *skb, u32 info)
 481{
 482        struct net *net = dev_net(skb->dev);
 483        const struct iphdr *iph = (const struct iphdr *)skb->data;
 484        struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
 485        struct xfrm_state *x;
 486
 487        switch (icmp_hdr(skb)->type) {
 488        case ICMP_DEST_UNREACH:
 489                if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
 490                        return;
 491        case ICMP_REDIRECT:
 492                break;
 493        default:
 494                return;
 495        }
 496
 497        x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
 498                              esph->spi, IPPROTO_ESP, AF_INET);
 499        if (!x)
 500                return;
 501
 502        if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
 503                ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
 504        else
 505                ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
 506        xfrm_state_put(x);
 507}
 508
 509static void esp_destroy(struct xfrm_state *x)
 510{
 511        struct esp_data *esp = x->data;
 512
 513        if (!esp)
 514                return;
 515
 516        crypto_free_aead(esp->aead);
 517        kfree(esp);
 518}
 519
 520static int esp_init_aead(struct xfrm_state *x)
 521{
 522        struct esp_data *esp = x->data;
 523        struct crypto_aead *aead;
 524        int err;
 525
 526        aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
 527        err = PTR_ERR(aead);
 528        if (IS_ERR(aead))
 529                goto error;
 530
 531        esp->aead = aead;
 532
 533        err = crypto_aead_setkey(aead, x->aead->alg_key,
 534                                 (x->aead->alg_key_len + 7) / 8);
 535        if (err)
 536                goto error;
 537
 538        err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
 539        if (err)
 540                goto error;
 541
 542error:
 543        return err;
 544}
 545
 546static int esp_init_authenc(struct xfrm_state *x)
 547{
 548        struct esp_data *esp = x->data;
 549        struct crypto_aead *aead;
 550        struct crypto_authenc_key_param *param;
 551        struct rtattr *rta;
 552        char *key;
 553        char *p;
 554        char authenc_name[CRYPTO_MAX_ALG_NAME];
 555        unsigned int keylen;
 556        int err;
 557
 558        err = -EINVAL;
 559        if (x->ealg == NULL)
 560                goto error;
 561
 562        err = -ENAMETOOLONG;
 563
 564        if ((x->props.flags & XFRM_STATE_ESN)) {
 565                if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
 566                             "authencesn(%s,%s)",
 567                             x->aalg ? x->aalg->alg_name : "digest_null",
 568                             x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
 569                        goto error;
 570        } else {
 571                if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
 572                             "authenc(%s,%s)",
 573                             x->aalg ? x->aalg->alg_name : "digest_null",
 574                             x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
 575                        goto error;
 576        }
 577
 578        aead = crypto_alloc_aead(authenc_name, 0, 0);
 579        err = PTR_ERR(aead);
 580        if (IS_ERR(aead))
 581                goto error;
 582
 583        esp->aead = aead;
 584
 585        keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
 586                 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
 587        err = -ENOMEM;
 588        key = kmalloc(keylen, GFP_KERNEL);
 589        if (!key)
 590                goto error;
 591
 592        p = key;
 593        rta = (void *)p;
 594        rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
 595        rta->rta_len = RTA_LENGTH(sizeof(*param));
 596        param = RTA_DATA(rta);
 597        p += RTA_SPACE(sizeof(*param));
 598
 599        if (x->aalg) {
 600                struct xfrm_algo_desc *aalg_desc;
 601
 602                memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
 603                p += (x->aalg->alg_key_len + 7) / 8;
 604
 605                aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
 606                BUG_ON(!aalg_desc);
 607
 608                err = -EINVAL;
 609                if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
 610                    crypto_aead_authsize(aead)) {
 611                        NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
 612                                 x->aalg->alg_name,
 613                                 crypto_aead_authsize(aead),
 614                                 aalg_desc->uinfo.auth.icv_fullbits/8);
 615                        goto free_key;
 616                }
 617
 618                err = crypto_aead_setauthsize(
 619                        aead, x->aalg->alg_trunc_len / 8);
 620                if (err)
 621                        goto free_key;
 622        }
 623
 624        param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
 625        memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
 626
 627        err = crypto_aead_setkey(aead, key, keylen);
 628
 629free_key:
 630        kfree(key);
 631
 632error:
 633        return err;
 634}
 635
 636static int esp_init_state(struct xfrm_state *x)
 637{
 638        struct esp_data *esp;
 639        struct crypto_aead *aead;
 640        u32 align;
 641        int err;
 642
 643        esp = kzalloc(sizeof(*esp), GFP_KERNEL);
 644        if (esp == NULL)
 645                return -ENOMEM;
 646
 647        x->data = esp;
 648
 649        if (x->aead)
 650                err = esp_init_aead(x);
 651        else
 652                err = esp_init_authenc(x);
 653
 654        if (err)
 655                goto error;
 656
 657        aead = esp->aead;
 658
 659        esp->padlen = 0;
 660
 661        x->props.header_len = sizeof(struct ip_esp_hdr) +
 662                              crypto_aead_ivsize(aead);
 663        if (x->props.mode == XFRM_MODE_TUNNEL)
 664                x->props.header_len += sizeof(struct iphdr);
 665        else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
 666                x->props.header_len += IPV4_BEET_PHMAXLEN;
 667        if (x->encap) {
 668                struct xfrm_encap_tmpl *encap = x->encap;
 669
 670                switch (encap->encap_type) {
 671                default:
 672                        goto error;
 673                case UDP_ENCAP_ESPINUDP:
 674                        x->props.header_len += sizeof(struct udphdr);
 675                        break;
 676                case UDP_ENCAP_ESPINUDP_NON_IKE:
 677                        x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
 678                        break;
 679                }
 680        }
 681
 682        align = ALIGN(crypto_aead_blocksize(aead), 4);
 683        if (esp->padlen)
 684                align = max_t(u32, align, esp->padlen);
 685        x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead);
 686
 687error:
 688        return err;
 689}
 690
 691static const struct xfrm_type esp_type =
 692{
 693        .description    = "ESP4",
 694        .owner          = THIS_MODULE,
 695        .proto          = IPPROTO_ESP,
 696        .flags          = XFRM_TYPE_REPLAY_PROT,
 697        .init_state     = esp_init_state,
 698        .destructor     = esp_destroy,
 699        .get_mtu        = esp4_get_mtu,
 700        .input          = esp_input,
 701        .output         = esp_output
 702};
 703
 704static const struct net_protocol esp4_protocol = {
 705        .handler        =       xfrm4_rcv,
 706        .err_handler    =       esp4_err,
 707        .no_policy      =       1,
 708        .netns_ok       =       1,
 709};
 710
 711static int __init esp4_init(void)
 712{
 713        if (xfrm_register_type(&esp_type, AF_INET) < 0) {
 714                pr_info("%s: can't add xfrm type\n", __func__);
 715                return -EAGAIN;
 716        }
 717        if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
 718                pr_info("%s: can't add protocol\n", __func__);
 719                xfrm_unregister_type(&esp_type, AF_INET);
 720                return -EAGAIN;
 721        }
 722        return 0;
 723}
 724
 725static void __exit esp4_fini(void)
 726{
 727        if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
 728                pr_info("%s: can't remove protocol\n", __func__);
 729        if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
 730                pr_info("%s: can't remove xfrm type\n", __func__);
 731}
 732
 733module_init(esp4_init);
 734module_exit(esp4_fini);
 735MODULE_LICENSE("GPL");
 736MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
 737
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.