sys/netipsec/xform_ipcomp.c

   1 /*      $FreeBSD$       */
   2 /* $OpenBSD: ip_ipcomp.c,v 1.1 2001/07/05 12:08:52 jjbg Exp $ */
   3
   4 /*-
   5  * Copyright (c) 2001 Jean-Jacques Bernard-Gundol (jj@wabbitt.org)
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *   notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *   notice, this list of conditions and the following disclaimer in the
  15  *   documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *   derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 /* IP payload compression protocol (IPComp), see RFC 2393 */
  32 #include "opt_inet.h"
  33 #include "opt_inet6.h"
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/mbuf.h>
  38 #include <sys/lock.h>
  39 #include <sys/mutex.h>
  40 #include <sys/socket.h>
  41 #include <sys/kernel.h>
  42 #include <sys/protosw.h>
  43 #include <sys/sysctl.h>
  44
  45 #include <netinet/in.h>
  46 #include <netinet/in_systm.h>
  47 #include <netinet/ip.h>
  48 #include <netinet/ip_var.h>
  49
  50 #include <net/route.h>
  51 #include <netipsec/ipsec.h>
  52 #include <netipsec/xform.h>
  53
  54 #ifdef INET6
  55 #include <netinet/ip6.h>
  56 #include <netipsec/ipsec6.h>
  57 #endif
  58
  59 #include <netipsec/ipcomp.h>
  60 #include <netipsec/ipcomp_var.h>
  61
  62 #include <netipsec/key.h>
  63 #include <netipsec/key_debug.h>
  64
  65 #include <opencrypto/cryptodev.h>
  66 #include <opencrypto/deflate.h>
  67 #include <opencrypto/xform.h>
  68
  69 int     ipcomp_enable = 0;
  70 struct  ipcompstat ipcompstat;
  71
  72 SYSCTL_DECL(_net_inet_ipcomp);
  73 SYSCTL_INT(_net_inet_ipcomp, OID_AUTO,
  74         ipcomp_enable,  CTLFLAG_RW,     &ipcomp_enable, 0, "");
  75 SYSCTL_STRUCT(_net_inet_ipcomp, IPSECCTL_STATS,
  76         stats,          CTLFLAG_RD,     &ipcompstat,    ipcompstat, "");
  77
  78 static int ipcomp_input_cb(struct cryptop *crp);
  79 static int ipcomp_output_cb(struct cryptop *crp);
  80
  81 struct comp_algo *
  82 ipcomp_algorithm_lookup(int alg)
  83 {
  84         if (alg >= IPCOMP_ALG_MAX)
  85                 return NULL;
  86         switch (alg) {
  87         case SADB_X_CALG_DEFLATE:
  88                 return &comp_algo_deflate;
  89         }
  90         return NULL;
  91 }
  92
  93 /*
  94  * ipcomp_init() is called when an CPI is being set up.
  95  */
  96 static int
  97 ipcomp_init(struct secasvar *sav, struct xformsw *xsp)
  98 {
  99         struct comp_algo *tcomp;
 100         struct cryptoini cric;
 101
 102         /* NB: algorithm really comes in alg_enc and not alg_comp! */
 103         tcomp = ipcomp_algorithm_lookup(sav->alg_enc);
 104         if (tcomp == NULL) {
 105                 DPRINTF(("%s: unsupported compression algorithm %d\n", __func__,
 106                          sav->alg_comp));
 107                 return EINVAL;
 108         }
 109         sav->alg_comp = sav->alg_enc;           /* set for doing histogram */
 110         sav->tdb_xform = xsp;
 111         sav->tdb_compalgxform = tcomp;
 112
 113         /* Initialize crypto session */
 114         bzero(&cric, sizeof (cric));
 115         cric.cri_alg = sav->tdb_compalgxform->type;
 116
 117         return crypto_newsession(&sav->tdb_cryptoid, &cric, crypto_support);
 118 }
 119
 120 /*
 121  * ipcomp_zeroize() used when IPCA is deleted
 122  */
 123 static int
 124 ipcomp_zeroize(struct secasvar *sav)
 125 {
 126         int err;
 127
 128         err = crypto_freesession(sav->tdb_cryptoid);
 129         sav->tdb_cryptoid = 0;
 130         return err;
 131 }
 132
 133 /*
 134  * ipcomp_input() gets called to uncompress an input packet
 135  */
 136 static int
 137 ipcomp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
 138 {
 139         struct tdb_crypto *tc;
 140         struct cryptodesc *crdc;
 141         struct cryptop *crp;
 142         int hlen = IPCOMP_HLENGTH;
 143
 144         IPSEC_SPLASSERT_SOFTNET(__func__);
 145
 146         /* Get crypto descriptors */
 147         crp = crypto_getreq(1);
 148         if (crp == NULL) {
 149                 m_freem(m);
 150                 DPRINTF(("%s: no crypto descriptors\n", __func__));
 151                 ipcompstat.ipcomps_crypto++;
 152                 return ENOBUFS;
 153         }
 154         /* Get IPsec-specific opaque pointer */
 155         tc = (struct tdb_crypto *) malloc(sizeof (*tc), M_XDATA, M_NOWAIT|M_ZERO);
 156         if (tc == NULL) {
 157                 m_freem(m);
 158                 crypto_freereq(crp);
 159                 DPRINTF(("%s: cannot allocate tdb_crypto\n", __func__));
 160                 ipcompstat.ipcomps_crypto++;
 161                 return ENOBUFS;
 162         }
 163         crdc = crp->crp_desc;
 164
 165         crdc->crd_skip = skip + hlen;
 166         crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
 167         crdc->crd_inject = skip;
 168
 169         tc->tc_ptr = 0;
 170
 171         /* Decompression operation */
 172         crdc->crd_alg = sav->tdb_compalgxform->type;
 173
 174         /* Crypto operation descriptor */
 175         crp->crp_ilen = m->m_pkthdr.len - (skip + hlen);
 176         crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
 177         crp->crp_buf = (caddr_t) m;
 178         crp->crp_callback = ipcomp_input_cb;
 179         crp->crp_sid = sav->tdb_cryptoid;
 180         crp->crp_opaque = (caddr_t) tc;
 181
 182         /* These are passed as-is to the callback */
 183         tc->tc_spi = sav->spi;
 184         tc->tc_dst = sav->sah->saidx.dst;
 185         tc->tc_proto = sav->sah->saidx.proto;
 186         tc->tc_protoff = protoff;
 187         tc->tc_skip = skip;
 188
 189         return crypto_dispatch(crp);
 190 }
 191
 192 #ifdef INET6
 193 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {              \
 194         if (saidx->dst.sa.sa_family == AF_INET6) {                           \
 195                 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
 196         } else {                                                             \
 197                 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
 198         }                                                                    \
 199 } while (0)
 200 #else
 201 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)                   \
 202         (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
 203 #endif
 204
 205 /*
 206  * IPComp input callback from the crypto driver.
 207  */
 208 static int
 209 ipcomp_input_cb(struct cryptop *crp)
 210 {
 211         struct cryptodesc *crd;
 212         struct tdb_crypto *tc;
 213         int skip, protoff;
 214         struct mtag *mtag;
 215         struct mbuf *m;
 216         struct secasvar *sav;
 217         struct secasindex *saidx;
 218         int hlen = IPCOMP_HLENGTH, error, clen;
 219         u_int8_t nproto;
 220         caddr_t addr;
 221
 222         crd = crp->crp_desc;
 223
 224         tc = (struct tdb_crypto *) crp->crp_opaque;
 225         IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
 226         skip = tc->tc_skip;
 227         protoff = tc->tc_protoff;
 228         mtag = (struct mtag *) tc->tc_ptr;
 229         m = (struct mbuf *) crp->crp_buf;
 230
 231         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
 232         if (sav == NULL) {
 233                 ipcompstat.ipcomps_notdb++;
 234                 DPRINTF(("%s: SA expired while in crypto\n", __func__));
 235                 error = ENOBUFS;                /*XXX*/
 236                 goto bad;
 237         }
 238
 239         saidx = &sav->sah->saidx;
 240         IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
 241                 saidx->dst.sa.sa_family == AF_INET6,
 242                 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
 243
 244         /* Check for crypto errors */
 245         if (crp->crp_etype) {
 246                 /* Reset the session ID */
 247                 if (sav->tdb_cryptoid != 0)
 248                         sav->tdb_cryptoid = crp->crp_sid;
 249
 250                 if (crp->crp_etype == EAGAIN) {
 251                         KEY_FREESAV(&sav);
 252                         return crypto_dispatch(crp);
 253                 }
 254
 255                 ipcompstat.ipcomps_noxform++;
 256                 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
 257                 error = crp->crp_etype;
 258                 goto bad;
 259         }
 260         /* Shouldn't happen... */
 261         if (m == NULL) {
 262                 ipcompstat.ipcomps_crypto++;
 263                 DPRINTF(("%s: null mbuf returned from crypto\n", __func__));
 264                 error = EINVAL;
 265                 goto bad;
 266         }
 267         ipcompstat.ipcomps_hist[sav->alg_comp]++;
 268
 269         clen = crp->crp_olen;           /* Length of data after processing */
 270
 271         /* Release the crypto descriptors */
 272         free(tc, M_XDATA), tc = NULL;
 273         crypto_freereq(crp), crp = NULL;
 274
 275         /* In case it's not done already, adjust the size of the mbuf chain */
 276         m->m_pkthdr.len = clen + hlen + skip;
 277
 278         if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
 279                 ipcompstat.ipcomps_hdrops++;            /*XXX*/
 280                 DPRINTF(("%s: m_pullup failed\n", __func__));
 281                 error = EINVAL;                         /*XXX*/
 282                 goto bad;
 283         }
 284
 285         /* Keep the next protocol field */
 286         addr = (caddr_t) mtod(m, struct ip *) + skip;
 287         nproto = ((struct ipcomp *) addr)->comp_nxt;
 288
 289         /* Remove the IPCOMP header */
 290         error = m_striphdr(m, skip, hlen);
 291         if (error) {
 292                 ipcompstat.ipcomps_hdrops++;
 293                 DPRINTF(("%s: bad mbuf chain, IPCA %s/%08lx\n", __func__,
 294                          ipsec_address(&sav->sah->saidx.dst),
 295                          (u_long) ntohl(sav->spi)));
 296                 goto bad;
 297         }
 298
 299         /* Restore the Next Protocol field */
 300         m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto);
 301
 302         IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, NULL);
 303
 304         KEY_FREESAV(&sav);
 305         return error;
 306 bad:
 307         if (sav)
 308                 KEY_FREESAV(&sav);
 309         if (m)
 310                 m_freem(m);
 311         if (tc != NULL)
 312                 free(tc, M_XDATA);
 313         if (crp)
 314                 crypto_freereq(crp);
 315         return error;
 316 }
 317
 318 /*
 319  * IPComp output routine, called by ipsec[46]_process_packet()
 320  */
 321 static int
 322 ipcomp_output(
 323         struct mbuf *m,
 324         struct ipsecrequest *isr,
 325         struct mbuf **mp,
 326         int skip,
 327         int protoff
 328 )
 329 {
 330         struct secasvar *sav;
 331         struct comp_algo *ipcompx;
 332         int error, ralen, hlen, maxpacketsize, roff;
 333         u_int8_t prot;
 334         struct cryptodesc *crdc;
 335         struct cryptop *crp;
 336         struct tdb_crypto *tc;
 337         struct mbuf *mo;
 338         struct ipcomp *ipcomp;
 339
 340         IPSEC_SPLASSERT_SOFTNET(__func__);
 341
 342         sav = isr->sav;
 343         IPSEC_ASSERT(sav != NULL, ("null SA"));
 344         ipcompx = sav->tdb_compalgxform;
 345         IPSEC_ASSERT(ipcompx != NULL, ("null compression xform"));
 346
 347         ralen = m->m_pkthdr.len - skip; /* Raw payload length before comp. */
 348         hlen = IPCOMP_HLENGTH;
 349
 350         ipcompstat.ipcomps_output++;
 351
 352         /* Check for maximum packet size violations. */
 353         switch (sav->sah->saidx.dst.sa.sa_family) {
 354 #ifdef INET
 355         case AF_INET:
 356                 maxpacketsize =  IP_MAXPACKET;
 357                 break;
 358 #endif /* INET */
 359 #ifdef INET6
 360         case AF_INET6:
 361                 maxpacketsize =  IPV6_MAXPACKET;
 362                 break;
 363 #endif /* INET6 */
 364         default:
 365                 ipcompstat.ipcomps_nopf++;
 366                 DPRINTF(("%s: unknown/unsupported protocol family %d, "
 367                     "IPCA %s/%08lx\n", __func__,
 368                     sav->sah->saidx.dst.sa.sa_family,
 369                     ipsec_address(&sav->sah->saidx.dst),
 370                     (u_long) ntohl(sav->spi)));
 371                 error = EPFNOSUPPORT;
 372                 goto bad;
 373         }
 374         if (skip + hlen + ralen > maxpacketsize) {
 375                 ipcompstat.ipcomps_toobig++;
 376                 DPRINTF(("%s: packet in IPCA %s/%08lx got too big "
 377                     "(len %u, max len %u)\n", __func__,
 378                     ipsec_address(&sav->sah->saidx.dst),
 379                     (u_long) ntohl(sav->spi),
 380                     skip + hlen + ralen, maxpacketsize));
 381                 error = EMSGSIZE;
 382                 goto bad;
 383         }
 384
 385         /* Update the counters */
 386         ipcompstat.ipcomps_obytes += m->m_pkthdr.len - skip;
 387
 388         m = m_clone(m);
 389         if (m == NULL) {
 390                 ipcompstat.ipcomps_hdrops++;
 391                 DPRINTF(("%s: cannot clone mbuf chain, IPCA %s/%08lx\n",
 392                     __func__, ipsec_address(&sav->sah->saidx.dst),
 393                     (u_long) ntohl(sav->spi)));
 394                 error = ENOBUFS;
 395                 goto bad;
 396         }
 397
 398         /* Inject IPCOMP header */
 399         mo = m_makespace(m, skip, hlen, &roff);
 400         if (mo == NULL) {
 401                 ipcompstat.ipcomps_wrap++;
 402                 DPRINTF(("%s: IPCOMP header inject failed for IPCA %s/%08lx\n",
 403                     __func__, ipsec_address(&sav->sah->saidx.dst),
 404                     (u_long) ntohl(sav->spi)));
 405                 error = ENOBUFS;
 406                 goto bad;
 407         }
 408         ipcomp = (struct ipcomp *)(mtod(mo, caddr_t) + roff);
 409
 410         /* Initialize the IPCOMP header */
 411         /* XXX alignment always correct? */
 412         switch (sav->sah->saidx.dst.sa.sa_family) {
 413 #ifdef INET
 414         case AF_INET:
 415                 ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p;
 416                 break;
 417 #endif /* INET */
 418 #ifdef INET6
 419         case AF_INET6:
 420                 ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt;
 421                 break;
 422 #endif
 423         }
 424         ipcomp->comp_flags = 0;
 425         ipcomp->comp_cpi = htons((u_int16_t) ntohl(sav->spi));
 426
 427         /* Fix Next Protocol in IPv4/IPv6 header */
 428         prot = IPPROTO_IPCOMP;
 429         m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
 430
 431         /* Ok now, we can pass to the crypto processing */
 432
 433         /* Get crypto descriptors */
 434         crp = crypto_getreq(1);
 435         if (crp == NULL) {
 436                 ipcompstat.ipcomps_crypto++;
 437                 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
 438                 error = ENOBUFS;
 439                 goto bad;
 440         }
 441         crdc = crp->crp_desc;
 442
 443         /* Compression descriptor */
 444         crdc->crd_skip = skip + hlen;
 445         crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
 446         crdc->crd_flags = CRD_F_COMP;
 447         crdc->crd_inject = skip + hlen;
 448
 449         /* Compression operation */
 450         crdc->crd_alg = ipcompx->type;
 451
 452         /* IPsec-specific opaque crypto info */
 453         tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
 454                 M_XDATA, M_NOWAIT|M_ZERO);
 455         if (tc == NULL) {
 456                 ipcompstat.ipcomps_crypto++;
 457                 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
 458                 crypto_freereq(crp);
 459                 error = ENOBUFS;
 460                 goto bad;
 461         }
 462
 463         tc->tc_isr = isr;
 464         tc->tc_spi = sav->spi;
 465         tc->tc_dst = sav->sah->saidx.dst;
 466         tc->tc_proto = sav->sah->saidx.proto;
 467         tc->tc_skip = skip + hlen;
 468
 469         /* Crypto operation descriptor */
 470         crp->crp_ilen = m->m_pkthdr.len;        /* Total input length */
 471         crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
 472         crp->crp_buf = (caddr_t) m;
 473         crp->crp_callback = ipcomp_output_cb;
 474         crp->crp_opaque = (caddr_t) tc;
 475         crp->crp_sid = sav->tdb_cryptoid;
 476
 477         return crypto_dispatch(crp);
 478 bad:
 479         if (m)
 480                 m_freem(m);
 481         return (error);
 482 }
 483
 484 /*
 485  * IPComp output callback from the crypto driver.
 486  */
 487 static int
 488 ipcomp_output_cb(struct cryptop *crp)
 489 {
 490         struct tdb_crypto *tc;
 491         struct ipsecrequest *isr;
 492         struct secasvar *sav;
 493         struct mbuf *m;
 494         int error, skip, rlen;
 495
 496         tc = (struct tdb_crypto *) crp->crp_opaque;
 497         IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
 498         m = (struct mbuf *) crp->crp_buf;
 499         skip = tc->tc_skip;
 500         rlen = crp->crp_ilen - skip;
 501
 502         isr = tc->tc_isr;
 503         IPSECREQUEST_LOCK(isr);
 504         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
 505         if (sav == NULL) {
 506                 ipcompstat.ipcomps_notdb++;
 507                 DPRINTF(("%s: SA expired while in crypto\n", __func__));
 508                 error = ENOBUFS;                /*XXX*/
 509                 goto bad;
 510         }
 511         IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
 512
 513         /* Check for crypto errors */
 514         if (crp->crp_etype) {
 515                 /* Reset session ID */
 516                 if (sav->tdb_cryptoid != 0)
 517                         sav->tdb_cryptoid = crp->crp_sid;
 518
 519                 if (crp->crp_etype == EAGAIN) {
 520                         KEY_FREESAV(&sav);
 521                         IPSECREQUEST_UNLOCK(isr);
 522                         return crypto_dispatch(crp);
 523                 }
 524                 ipcompstat.ipcomps_noxform++;
 525                 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
 526                 error = crp->crp_etype;
 527                 goto bad;
 528         }
 529         /* Shouldn't happen... */
 530         if (m == NULL) {
 531                 ipcompstat.ipcomps_crypto++;
 532                 DPRINTF(("%s: bogus return buffer from crypto\n", __func__));
 533                 error = EINVAL;
 534                 goto bad;
 535         }
 536         ipcompstat.ipcomps_hist[sav->alg_comp]++;
 537
 538         if (rlen > crp->crp_olen) {
 539                 /* Adjust the length in the IP header */
 540                 switch (sav->sah->saidx.dst.sa.sa_family) {
 541 #ifdef INET
 542                 case AF_INET:
 543                         mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
 544                         break;
 545 #endif /* INET */
 546 #ifdef INET6
 547                 case AF_INET6:
 548                         mtod(m, struct ip6_hdr *)->ip6_plen =
 549                                 htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr);
 550                         break;
 551 #endif /* INET6 */
 552                 default:
 553                         ipcompstat.ipcomps_nopf++;
 554                         DPRINTF(("%s: unknown/unsupported protocol "
 555                             "family %d, IPCA %s/%08lx\n", __func__,
 556                             sav->sah->saidx.dst.sa.sa_family,
 557                             ipsec_address(&sav->sah->saidx.dst),
 558                             (u_long) ntohl(sav->spi)));
 559                         error = EPFNOSUPPORT;
 560                         goto bad;
 561                 }
 562         } else {
 563                 /* compression was useless, we have lost time */
 564                 /* XXX add statistic */
 565         }
 566
 567         /* Release the crypto descriptor */
 568         free(tc, M_XDATA);
 569         crypto_freereq(crp);
 570
 571         /* NB: m is reclaimed by ipsec_process_done. */
 572         error = ipsec_process_done(m, isr);
 573         KEY_FREESAV(&sav);
 574         IPSECREQUEST_UNLOCK(isr);
 575
 576         return error;
 577 bad:
 578         if (sav)
 579                 KEY_FREESAV(&sav);
 580         IPSECREQUEST_UNLOCK(isr);
 581         if (m)
 582                 m_freem(m);
 583         free(tc, M_XDATA);
 584         crypto_freereq(crp);
 585         return error;
 586 }
 587
 588 static struct xformsw ipcomp_xformsw = {
 589         XF_IPCOMP,              XFT_COMP,               "IPcomp",
 590         ipcomp_init,            ipcomp_zeroize,         ipcomp_input,
 591         ipcomp_output
 592 };
 593
 594 static void
 595 ipcomp_attach(void)
 596 {
 597         xform_register(&ipcomp_xformsw);
 598 }
 599 SYSINIT(ipcomp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipcomp_attach, NULL);