sys/netproto/ipsec/xform_ipcomp.c

   1 /*      $FreeBSD: src/sys/netipsec/xform_ipcomp.c,v 1.1.4.2 2003/02/26 00:14:06 sam Exp $       */
   2 /*      $DragonFly: src/sys/netproto/ipsec/xform_ipcomp.c,v 1.7 2005/06/10 23:59:31 dillon Exp $        */
   3 /* $OpenBSD: ip_ipcomp.c,v 1.1 2001/07/05 12:08:52 jjbg Exp $ */
   4
   5 /*
   6  * Copyright (c) 2001 Jean-Jacques Bernard-Gundol (jj@wabbitt.org)
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *   notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *   notice, this list of conditions and the following disclaimer in the
  16  *   documentation and/or other materials provided with the distribution.
  17  * 3. The name of the author may not be used to endorse or promote products
  18  *   derived from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /* IP payload compression protocol (IPComp), see RFC 2393 */
  33 #include "opt_inet.h"
  34 #include "opt_inet6.h"
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/mbuf.h>
  39 #include <sys/socket.h>
  40 #include <sys/kernel.h>
  41 #include <sys/protosw.h>
  42 #include <sys/sysctl.h>
  43
  44 #include <netinet/in.h>
  45 #include <netinet/in_systm.h>
  46 #include <netinet/ip.h>
  47 #include <netinet/ip_var.h>
  48
  49 #include <net/route.h>
  50 #include <netproto/ipsec/ipsec.h>
  51 #include <netproto/ipsec/xform.h>
  52
  53 #ifdef INET6
  54 #include <netinet/ip6.h>
  55 #include <netproto/ipsec/ipsec6.h>
  56 #endif
  57
  58 #include <netproto/ipsec/ipcomp.h>
  59 #include <netproto/ipsec/ipcomp_var.h>
  60
  61 #include <netproto/ipsec/key.h>
  62 #include <netproto/ipsec/key_debug.h>
  63
  64 #include <opencrypto/cryptodev.h>
  65 #include <opencrypto/deflate.h>
  66 #include <opencrypto/xform.h>
  67
  68 int     ipcomp_enable = 0;
  69 struct  ipcompstat ipcompstat;
  70
  71 SYSCTL_DECL(_net_inet_ipcomp);
  72 SYSCTL_INT(_net_inet_ipcomp, OID_AUTO,
  73         ipcomp_enable,  CTLFLAG_RW,     &ipcomp_enable, 0, "");
  74 SYSCTL_STRUCT(_net_inet_ipcomp, IPSECCTL_STATS,
  75         stats,          CTLFLAG_RD,     &ipcompstat,    ipcompstat, "");
  76
  77 static int ipcomp_input_cb(struct cryptop *crp);
  78 static int ipcomp_output_cb(struct cryptop *crp);
  79
  80 struct comp_algo *
  81 ipcomp_algorithm_lookup(int alg)
  82 {
  83         if (alg >= IPCOMP_ALG_MAX)
  84                 return NULL;
  85         switch (alg) {
  86         case SADB_X_CALG_DEFLATE:
  87                 return &comp_algo_deflate;
  88         }
  89         return NULL;
  90 }
  91
  92 /*
  93  * ipcomp_init() is called when an CPI is being set up.
  94  */
  95 static int
  96 ipcomp_init(struct secasvar *sav, struct xformsw *xsp)
  97 {
  98         struct comp_algo *tcomp;
  99         struct cryptoini cric;
 100
 101         /* NB: algorithm really comes in alg_enc and not alg_comp! */
 102         tcomp = ipcomp_algorithm_lookup(sav->alg_enc);
 103         if (tcomp == NULL) {
 104                 DPRINTF(("ipcomp_init: unsupported compression algorithm %d\n",
 105                          sav->alg_comp));
 106                 return EINVAL;
 107         }
 108         sav->alg_comp = sav->alg_enc;           /* set for doing histogram */
 109         sav->tdb_xform = xsp;
 110         sav->tdb_compalgxform = tcomp;
 111
 112         /* Initialize crypto session */
 113         bzero(&cric, sizeof (cric));
 114         cric.cri_alg = sav->tdb_compalgxform->type;
 115
 116         return crypto_newsession(&sav->tdb_cryptoid, &cric, crypto_support);
 117 }
 118
 119 /*
 120  * ipcomp_zeroize() used when IPCA is deleted
 121  */
 122 static int
 123 ipcomp_zeroize(struct secasvar *sav)
 124 {
 125         int err;
 126
 127         err = crypto_freesession(sav->tdb_cryptoid);
 128         sav->tdb_cryptoid = 0;
 129         return err;
 130 }
 131
 132 /*
 133  * ipcomp_input() gets called to uncompress an input packet
 134  */
 135 static int
 136 ipcomp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
 137 {
 138         struct tdb_crypto *tc;
 139         struct cryptodesc *crdc;
 140         struct cryptop *crp;
 141         int hlen = IPCOMP_HLENGTH;
 142
 143         /* Get crypto descriptors */
 144         crp = crypto_getreq(1);
 145         if (crp == NULL) {
 146                 m_freem(m);
 147                 DPRINTF(("ipcomp_input: no crypto descriptors\n"));
 148                 ipcompstat.ipcomps_crypto++;
 149                 return ENOBUFS;
 150         }
 151         /* Get IPsec-specific opaque pointer */
 152         tc = malloc(sizeof (*tc), M_XDATA,
 153                     M_INTWAIT | M_ZERO | M_NULLOK);
 154         if (tc == NULL) {
 155                 m_freem(m);
 156                 crypto_freereq(crp);
 157                 DPRINTF(("ipcomp_input: cannot allocate tdb_crypto\n"));
 158                 ipcompstat.ipcomps_crypto++;
 159                 return ENOBUFS;
 160         }
 161         crdc = crp->crp_desc;
 162
 163         crdc->crd_skip = skip + hlen;
 164         crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
 165         crdc->crd_inject = skip;
 166
 167         tc->tc_ptr = 0;
 168
 169         /* Decompression operation */
 170         crdc->crd_alg = sav->tdb_compalgxform->type;
 171
 172         /* Crypto operation descriptor */
 173         crp->crp_ilen = m->m_pkthdr.len - (skip + hlen);
 174         crp->crp_flags = CRYPTO_F_IMBUF;
 175         crp->crp_buf = (caddr_t) m;
 176         crp->crp_callback = ipcomp_input_cb;
 177         crp->crp_sid = sav->tdb_cryptoid;
 178         crp->crp_opaque = (caddr_t) tc;
 179
 180         /* These are passed as-is to the callback */
 181         tc->tc_spi = sav->spi;
 182         tc->tc_dst = sav->sah->saidx.dst;
 183         tc->tc_proto = sav->sah->saidx.proto;
 184         tc->tc_protoff = protoff;
 185         tc->tc_skip = skip;
 186
 187         return crypto_dispatch(crp);
 188 }
 189
 190 #ifdef INET6
 191 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {              \
 192         if (saidx->dst.sa.sa_family == AF_INET6) {                           \
 193                 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
 194         } else {                                                             \
 195                 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
 196         }                                                                    \
 197 } while (0)
 198 #else
 199 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)                   \
 200         (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
 201 #endif
 202
 203 /*
 204  * IPComp input callback from the crypto driver.
 205  */
 206 static int
 207 ipcomp_input_cb(struct cryptop *crp)
 208 {
 209         struct cryptodesc *crd;
 210         struct tdb_crypto *tc;
 211         int skip, protoff;
 212         struct mtag *mtag;
 213         struct mbuf *m;
 214         struct secasvar *sav;
 215         struct secasindex *saidx;
 216         int hlen = IPCOMP_HLENGTH, error, clen;
 217         u_int8_t nproto;
 218         caddr_t addr;
 219
 220         crd = crp->crp_desc;
 221
 222         tc = (struct tdb_crypto *) crp->crp_opaque;
 223         KASSERT(tc != NULL, ("ipcomp_input_cb: null opaque crypto data area!"));
 224         skip = tc->tc_skip;
 225         protoff = tc->tc_protoff;
 226         mtag = (struct mtag *) tc->tc_ptr;
 227         m = (struct mbuf *) crp->crp_buf;
 228
 229         crit_enter();
 230
 231         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
 232         if (sav == NULL) {
 233                 ipcompstat.ipcomps_notdb++;
 234                 DPRINTF(("ipcomp_input_cb: SA expired while in crypto\n"));
 235                 error = ENOBUFS;                /*XXX*/
 236                 goto bad;
 237         }
 238
 239         saidx = &sav->sah->saidx;
 240         KASSERT(saidx->dst.sa.sa_family == AF_INET ||
 241                 saidx->dst.sa.sa_family == AF_INET6,
 242                 ("ah_input_cb: unexpected protocol family %u",
 243                  saidx->dst.sa.sa_family));
 244
 245         /* Check for crypto errors */
 246         if (crp->crp_etype) {
 247                 /* Reset the session ID */
 248                 if (sav->tdb_cryptoid != 0)
 249                         sav->tdb_cryptoid = crp->crp_sid;
 250
 251                 if (crp->crp_etype == EAGAIN) {
 252                         KEY_FREESAV(&sav);
 253                         crit_exit();
 254                         return crypto_dispatch(crp);
 255                 }
 256
 257                 ipcompstat.ipcomps_noxform++;
 258                 DPRINTF(("ipcomp_input_cb: crypto error %d\n", crp->crp_etype));
 259                 error = crp->crp_etype;
 260                 goto bad;
 261         }
 262         /* Shouldn't happen... */
 263         if (m == NULL) {
 264                 ipcompstat.ipcomps_crypto++;
 265                 DPRINTF(("ipcomp_input_cb: null mbuf returned from crypto\n"));
 266                 error = EINVAL;
 267                 goto bad;
 268         }
 269         ipcompstat.ipcomps_hist[sav->alg_comp]++;
 270
 271         clen = crp->crp_olen;           /* Length of data after processing */
 272
 273         /* Release the crypto descriptors */
 274         free(tc, M_XDATA), tc = NULL;
 275         crypto_freereq(crp), crp = NULL;
 276
 277         /* In case it's not done already, adjust the size of the mbuf chain */
 278         m->m_pkthdr.len = clen + hlen + skip;
 279
 280         if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
 281                 ipcompstat.ipcomps_hdrops++;            /*XXX*/
 282                 DPRINTF(("ipcomp_input_cb: m_pullup failed\n"));
 283                 error = EINVAL;                         /*XXX*/
 284                 goto bad;
 285         }
 286
 287         /* Keep the next protocol field */
 288         addr = (caddr_t) mtod(m, struct ip *) + skip;
 289         nproto = ((struct ipcomp *) addr)->comp_nxt;
 290
 291         /* Remove the IPCOMP header */
 292         error = m_striphdr(m, skip, hlen);
 293         if (error) {
 294                 ipcompstat.ipcomps_hdrops++;
 295                 DPRINTF(("ipcomp_input_cb: bad mbuf chain, IPCA %s/%08lx\n",
 296                          ipsec_address(&sav->sah->saidx.dst),
 297                          (u_long) ntohl(sav->spi)));
 298                 goto bad;
 299         }
 300
 301         /* Restore the Next Protocol field */
 302         m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto);
 303
 304         IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, NULL);
 305
 306         KEY_FREESAV(&sav);
 307         crit_exit();
 308         return error;
 309 bad:
 310         if (sav)
 311                 KEY_FREESAV(&sav);
 312         crit_exit();
 313         if (m)
 314                 m_freem(m);
 315         if (tc != NULL)
 316                 free(tc, M_XDATA);
 317         if (crp)
 318                 crypto_freereq(crp);
 319         return error;
 320 }
 321
 322 /*
 323  * IPComp output routine, called by ipsec[46]_process_packet()
 324  */
 325 static int
 326 ipcomp_output(
 327         struct mbuf *m,
 328         struct ipsecrequest *isr,
 329         struct mbuf **mp,
 330         int skip,
 331         int protoff
 332 )
 333 {
 334         struct secasvar *sav;
 335         struct comp_algo *ipcompx;
 336         int error, ralen, hlen, maxpacketsize, roff;
 337         u_int8_t prot;
 338         struct cryptodesc *crdc;
 339         struct cryptop *crp;
 340         struct tdb_crypto *tc;
 341         struct mbuf *mo;
 342         struct ipcomp *ipcomp;
 343
 344         sav = isr->sav;
 345         KASSERT(sav != NULL, ("ipcomp_output: null SA"));
 346         ipcompx = sav->tdb_compalgxform;
 347         KASSERT(ipcompx != NULL, ("ipcomp_output: null compression xform"));
 348
 349         ralen = m->m_pkthdr.len - skip; /* Raw payload length before comp. */
 350         hlen = IPCOMP_HLENGTH;
 351
 352         ipcompstat.ipcomps_output++;
 353
 354         /* Check for maximum packet size violations. */
 355         switch (sav->sah->saidx.dst.sa.sa_family) {
 356 #ifdef INET
 357         case AF_INET:
 358                 maxpacketsize =  IP_MAXPACKET;
 359                 break;
 360 #endif /* INET */
 361 #ifdef INET6
 362         case AF_INET6:
 363                 maxpacketsize =  IPV6_MAXPACKET;
 364                 break;
 365 #endif /* INET6 */
 366         default:
 367                 ipcompstat.ipcomps_nopf++;
 368                 DPRINTF(("ipcomp_output: unknown/unsupported protocol family %d"
 369                     ", IPCA %s/%08lx\n",
 370                     sav->sah->saidx.dst.sa.sa_family,
 371                     ipsec_address(&sav->sah->saidx.dst),
 372                     (u_long) ntohl(sav->spi)));
 373                 error = EPFNOSUPPORT;
 374                 goto bad;
 375         }
 376         if (skip + hlen + ralen > maxpacketsize) {
 377                 ipcompstat.ipcomps_toobig++;
 378                 DPRINTF(("ipcomp_output: packet in IPCA %s/%08lx got too big "
 379                     "(len %u, max len %u)\n",
 380                     ipsec_address(&sav->sah->saidx.dst),
 381                     (u_long) ntohl(sav->spi),
 382                     skip + hlen + ralen, maxpacketsize));
 383                 error = EMSGSIZE;
 384                 goto bad;
 385         }
 386
 387         /* Update the counters */
 388         ipcompstat.ipcomps_obytes += m->m_pkthdr.len - skip;
 389
 390         m = m_clone(m);
 391         if (m == NULL) {
 392                 ipcompstat.ipcomps_hdrops++;
 393                 DPRINTF(("ipcomp_output: cannot clone mbuf chain, IPCA %s/%08lx\n",
 394                     ipsec_address(&sav->sah->saidx.dst),
 395                     (u_long) ntohl(sav->spi)));
 396                 error = ENOBUFS;
 397                 goto bad;
 398         }
 399
 400         /* Inject IPCOMP header */
 401         mo = m_makespace(m, skip, hlen, &roff);
 402         if (mo == NULL) {
 403                 ipcompstat.ipcomps_wrap++;
 404                 DPRINTF(("ipcomp_output: failed to inject IPCOMP header for "
 405                     "IPCA %s/%08lx\n",
 406                     ipsec_address(&sav->sah->saidx.dst),
 407                     (u_long) ntohl(sav->spi)));
 408                 error = ENOBUFS;
 409                 goto bad;
 410         }
 411         ipcomp = (struct ipcomp *)(mtod(mo, caddr_t) + roff);
 412
 413         /* Initialize the IPCOMP header */
 414         /* XXX alignment always correct? */
 415         switch (sav->sah->saidx.dst.sa.sa_family) {
 416 #ifdef INET
 417         case AF_INET:
 418                 ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p;
 419                 break;
 420 #endif /* INET */
 421 #ifdef INET6
 422         case AF_INET6:
 423                 ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt;
 424                 break;
 425 #endif
 426         }
 427         ipcomp->comp_flags = 0;
 428         ipcomp->comp_cpi = htons((u_int16_t) ntohl(sav->spi));
 429
 430         /* Fix Next Protocol in IPv4/IPv6 header */
 431         prot = IPPROTO_IPCOMP;
 432         m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
 433
 434         /* Ok now, we can pass to the crypto processing */
 435
 436         /* Get crypto descriptors */
 437         crp = crypto_getreq(1);
 438         if (crp == NULL) {
 439                 ipcompstat.ipcomps_crypto++;
 440                 DPRINTF(("ipcomp_output: failed to acquire crypto descriptor\n"));
 441                 error = ENOBUFS;
 442                 goto bad;
 443         }
 444         crdc = crp->crp_desc;
 445
 446         /* Compression descriptor */
 447         crdc->crd_skip = skip + hlen;
 448         crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
 449         crdc->crd_flags = CRD_F_COMP;
 450         crdc->crd_inject = skip + hlen;
 451
 452         /* Compression operation */
 453         crdc->crd_alg = ipcompx->type;
 454
 455         /* IPsec-specific opaque crypto info */
 456         tc = malloc(sizeof(struct tdb_crypto),
 457                     M_XDATA, M_INTWAIT | M_ZERO | M_NULLOK);
 458         if (tc == NULL) {
 459                 ipcompstat.ipcomps_crypto++;
 460                 DPRINTF(("ipcomp_output: failed to allocate tdb_crypto\n"));
 461                 crypto_freereq(crp);
 462                 error = ENOBUFS;
 463                 goto bad;
 464         }
 465
 466         tc->tc_isr = isr;
 467         tc->tc_spi = sav->spi;
 468         tc->tc_dst = sav->sah->saidx.dst;
 469         tc->tc_proto = sav->sah->saidx.proto;
 470         tc->tc_skip = skip + hlen;
 471
 472         /* Crypto operation descriptor */
 473         crp->crp_ilen = m->m_pkthdr.len;        /* Total input length */
 474         crp->crp_flags = CRYPTO_F_IMBUF;
 475         crp->crp_buf = (caddr_t) m;
 476         crp->crp_callback = ipcomp_output_cb;
 477         crp->crp_opaque = (caddr_t) tc;
 478         crp->crp_sid = sav->tdb_cryptoid;
 479
 480         return crypto_dispatch(crp);
 481 bad:
 482         if (m)
 483                 m_freem(m);
 484         return (error);
 485 }
 486
 487 /*
 488  * IPComp output callback from the crypto driver.
 489  */
 490 static int
 491 ipcomp_output_cb(struct cryptop *crp)
 492 {
 493         struct tdb_crypto *tc;
 494         struct ipsecrequest *isr;
 495         struct secasvar *sav;
 496         struct mbuf *m;
 497         int error, skip, rlen;
 498
 499         tc = (struct tdb_crypto *) crp->crp_opaque;
 500         KASSERT(tc != NULL, ("ipcomp_output_cb: null opaque data area!"));
 501         m = (struct mbuf *) crp->crp_buf;
 502         skip = tc->tc_skip;
 503         rlen = crp->crp_ilen - skip;
 504
 505         crit_enter();
 506
 507         isr = tc->tc_isr;
 508         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
 509         if (sav == NULL) {
 510                 ipcompstat.ipcomps_notdb++;
 511                 DPRINTF(("ipcomp_output_cb: SA expired while in crypto\n"));
 512                 error = ENOBUFS;                /*XXX*/
 513                 goto bad;
 514         }
 515         KASSERT(isr->sav == sav, ("ipcomp_output_cb: SA changed\n"));
 516
 517         /* Check for crypto errors */
 518         if (crp->crp_etype) {
 519                 /* Reset session ID */
 520                 if (sav->tdb_cryptoid != 0)
 521                         sav->tdb_cryptoid = crp->crp_sid;
 522
 523                 if (crp->crp_etype == EAGAIN) {
 524                         KEY_FREESAV(&sav);
 525                         crit_exit();
 526                         return crypto_dispatch(crp);
 527                 }
 528                 ipcompstat.ipcomps_noxform++;
 529                 DPRINTF(("ipcomp_output_cb: crypto error %d\n", crp->crp_etype));
 530                 error = crp->crp_etype;
 531                 goto bad;
 532         }
 533         /* Shouldn't happen... */
 534         if (m == NULL) {
 535                 ipcompstat.ipcomps_crypto++;
 536                 DPRINTF(("ipcomp_output_cb: bogus return buffer from crypto\n"));
 537                 error = EINVAL;
 538                 goto bad;
 539         }
 540         ipcompstat.ipcomps_hist[sav->alg_comp]++;
 541
 542         if (rlen > crp->crp_olen) {
 543                 /* Adjust the length in the IP header */
 544                 switch (sav->sah->saidx.dst.sa.sa_family) {
 545 #ifdef INET
 546                 case AF_INET:
 547                         mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
 548                         break;
 549 #endif /* INET */
 550 #ifdef INET6
 551                 case AF_INET6:
 552                         mtod(m, struct ip6_hdr *)->ip6_plen =
 553                                 htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr);
 554                         break;
 555 #endif /* INET6 */
 556                 default:
 557                         ipcompstat.ipcomps_nopf++;
 558                         DPRINTF(("ipcomp_output: unknown/unsupported protocol "
 559                             "family %d, IPCA %s/%08lx\n",
 560                             sav->sah->saidx.dst.sa.sa_family,
 561                             ipsec_address(&sav->sah->saidx.dst),
 562                             (u_long) ntohl(sav->spi)));
 563                         error = EPFNOSUPPORT;
 564                         goto bad;
 565                 }
 566         } else {
 567                 /* compression was useless, we have lost time */
 568                 /* XXX add statistic */
 569         }
 570
 571         /* Release the crypto descriptor */
 572         free(tc, M_XDATA);
 573         crypto_freereq(crp);
 574
 575         /* NB: m is reclaimed by ipsec_process_done. */
 576         error = ipsec_process_done(m, isr);
 577         KEY_FREESAV(&sav);
 578         crit_exit();
 579         return error;
 580 bad:
 581         if (sav)
 582                 KEY_FREESAV(&sav);
 583         crit_exit();
 584         if (m)
 585                 m_freem(m);
 586         free(tc, M_XDATA);
 587         crypto_freereq(crp);
 588         return error;
 589 }
 590
 591 static struct xformsw ipcomp_xformsw = {
 592         XF_IPCOMP,              XFT_COMP,               "IPcomp",
 593         ipcomp_init,            ipcomp_zeroize,         ipcomp_input,
 594         ipcomp_output
 595 };
 596
 597 static void
 598 ipcomp_attach(void)
 599 {
 600         xform_register(&ipcomp_xformsw);
 601 }
 602 SYSINIT(ipcomp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, ipcomp_attach, NULL)