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/rwlock.h>
  41 #include <sys/socket.h>
  42 #include <sys/kernel.h>
  43 #include <sys/protosw.h>
  44 #include <sys/sysctl.h>
  45
  46 #include <netinet/in.h>
  47 #include <netinet/in_systm.h>
  48 #include <netinet/ip.h>
  49 #include <netinet/ip_var.h>
  50
  51 #include <net/vnet.h>
  52
  53 #include <netipsec/ipsec.h>
  54 #include <netipsec/xform.h>
  55
  56 #ifdef INET6
  57 #include <netinet/ip6.h>
  58 #include <netipsec/ipsec6.h>
  59 #endif
  60
  61 #include <netipsec/ipcomp.h>
  62 #include <netipsec/ipcomp_var.h>
  63
  64 #include <netipsec/key.h>
  65 #include <netipsec/key_debug.h>
  66
  67 #include <opencrypto/cryptodev.h>
  68 #include <opencrypto/deflate.h>
  69 #include <opencrypto/xform.h>
  70
  71 VNET_DEFINE(int, ipcomp_enable) = 1;
  72 VNET_PCPUSTAT_DEFINE(struct ipcompstat, ipcompstat);
  73 VNET_PCPUSTAT_SYSINIT(ipcompstat);
  74
  75 #ifdef VIMAGE
  76 VNET_PCPUSTAT_SYSUNINIT(ipcompstat);
  77 #endif /* VIMAGE */
  78
  79 SYSCTL_DECL(_net_inet_ipcomp);
  80 SYSCTL_INT(_net_inet_ipcomp, OID_AUTO, ipcomp_enable,
  81         CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipcomp_enable), 0, "");
  82 SYSCTL_VNET_PCPUSTAT(_net_inet_ipcomp, IPSECCTL_STATS, stats,
  83     struct ipcompstat, ipcompstat,
  84     "IPCOMP statistics (struct ipcompstat, netipsec/ipcomp_var.h");
  85
  86 static int ipcomp_input_cb(struct cryptop *crp);
  87 static int ipcomp_output_cb(struct cryptop *crp);
  88
  89 struct comp_algo *
  90 ipcomp_algorithm_lookup(int alg)
  91 {
  92         if (alg >= IPCOMP_ALG_MAX)
  93                 return NULL;
  94         switch (alg) {
  95         case SADB_X_CALG_DEFLATE:
  96                 return &comp_algo_deflate;
  97         }
  98         return NULL;
  99 }
 100
 101 /*
 102  * ipcomp_init() is called when an CPI is being set up.
 103  */
 104 static int
 105 ipcomp_init(struct secasvar *sav, struct xformsw *xsp)
 106 {
 107         struct comp_algo *tcomp;
 108         struct cryptoini cric;
 109
 110         /* NB: algorithm really comes in alg_enc and not alg_comp! */
 111         tcomp = ipcomp_algorithm_lookup(sav->alg_enc);
 112         if (tcomp == NULL) {
 113                 DPRINTF(("%s: unsupported compression algorithm %d\n", __func__,
 114                          sav->alg_comp));
 115                 return EINVAL;
 116         }
 117         sav->alg_comp = sav->alg_enc;           /* set for doing histogram */
 118         sav->tdb_xform = xsp;
 119         sav->tdb_compalgxform = tcomp;
 120
 121         /* Initialize crypto session */
 122         bzero(&cric, sizeof (cric));
 123         cric.cri_alg = sav->tdb_compalgxform->type;
 124
 125         return crypto_newsession(&sav->tdb_cryptoid, &cric, V_crypto_support);
 126 }
 127
 128 /*
 129  * ipcomp_zeroize() used when IPCA is deleted
 130  */
 131 static int
 132 ipcomp_zeroize(struct secasvar *sav)
 133 {
 134         int err;
 135
 136         err = crypto_freesession(sav->tdb_cryptoid);
 137         sav->tdb_cryptoid = 0;
 138         return err;
 139 }
 140
 141 /*
 142  * ipcomp_input() gets called to uncompress an input packet
 143  */
 144 static int
 145 ipcomp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
 146 {
 147         struct tdb_crypto *tc;
 148         struct cryptodesc *crdc;
 149         struct cryptop *crp;
 150         struct ipcomp *ipcomp;
 151         caddr_t addr;
 152         int hlen = IPCOMP_HLENGTH;
 153
 154         /*
 155          * Check that the next header of the IPComp is not IPComp again, before
 156          * doing any real work.  Given it is not possible to do double
 157          * compression it means someone is playing tricks on us.
 158          */
 159         if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == NULL) {
 160                 IPCOMPSTAT_INC(ipcomps_hdrops);         /*XXX*/
 161                 DPRINTF(("%s: m_pullup failed\n", __func__));
 162                 return (ENOBUFS);
 163         }
 164         addr = (caddr_t) mtod(m, struct ip *) + skip;
 165         ipcomp = (struct ipcomp *)addr;
 166         if (ipcomp->comp_nxt == IPPROTO_IPCOMP) {
 167                 m_freem(m);
 168                 IPCOMPSTAT_INC(ipcomps_pdrops); /* XXX have our own stats? */
 169                 DPRINTF(("%s: recursive compression detected\n", __func__));
 170                 return (EINVAL);
 171         }
 172
 173         /* Get crypto descriptors */
 174         crp = crypto_getreq(1);
 175         if (crp == NULL) {
 176                 m_freem(m);
 177                 DPRINTF(("%s: no crypto descriptors\n", __func__));
 178                 IPCOMPSTAT_INC(ipcomps_crypto);
 179                 return ENOBUFS;
 180         }
 181         /* Get IPsec-specific opaque pointer */
 182         tc = (struct tdb_crypto *) malloc(sizeof (*tc), M_XDATA, M_NOWAIT|M_ZERO);
 183         if (tc == NULL) {
 184                 m_freem(m);
 185                 crypto_freereq(crp);
 186                 DPRINTF(("%s: cannot allocate tdb_crypto\n", __func__));
 187                 IPCOMPSTAT_INC(ipcomps_crypto);
 188                 return ENOBUFS;
 189         }
 190         crdc = crp->crp_desc;
 191
 192         crdc->crd_skip = skip + hlen;
 193         crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
 194         crdc->crd_inject = skip;
 195
 196         tc->tc_ptr = 0;
 197
 198         /* Decompression operation */
 199         crdc->crd_alg = sav->tdb_compalgxform->type;
 200
 201         /* Crypto operation descriptor */
 202         crp->crp_ilen = m->m_pkthdr.len - (skip + hlen);
 203         crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
 204         crp->crp_buf = (caddr_t) m;
 205         crp->crp_callback = ipcomp_input_cb;
 206         crp->crp_sid = sav->tdb_cryptoid;
 207         crp->crp_opaque = (caddr_t) tc;
 208
 209         /* These are passed as-is to the callback */
 210         tc->tc_spi = sav->spi;
 211         tc->tc_dst = sav->sah->saidx.dst;
 212         tc->tc_proto = sav->sah->saidx.proto;
 213         tc->tc_protoff = protoff;
 214         tc->tc_skip = skip;
 215         KEY_ADDREFSA(sav);
 216         tc->tc_sav = sav;
 217
 218         return crypto_dispatch(crp);
 219 }
 220
 221 /*
 222  * IPComp input callback from the crypto driver.
 223  */
 224 static int
 225 ipcomp_input_cb(struct cryptop *crp)
 226 {
 227         char buf[INET6_ADDRSTRLEN];
 228         struct cryptodesc *crd;
 229         struct tdb_crypto *tc;
 230         int skip, protoff;
 231         struct mbuf *m;
 232         struct secasvar *sav;
 233         struct secasindex *saidx;
 234         int hlen = IPCOMP_HLENGTH, error, clen;
 235         u_int8_t nproto;
 236         caddr_t addr;
 237
 238         crd = crp->crp_desc;
 239
 240         tc = (struct tdb_crypto *) crp->crp_opaque;
 241         IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
 242         skip = tc->tc_skip;
 243         protoff = tc->tc_protoff;
 244         m = (struct mbuf *) crp->crp_buf;
 245
 246         sav = tc->tc_sav;
 247         IPSEC_ASSERT(sav != NULL, ("null SA!"));
 248
 249         saidx = &sav->sah->saidx;
 250         IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
 251                 saidx->dst.sa.sa_family == AF_INET6,
 252                 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
 253
 254         /* Check for crypto errors */
 255         if (crp->crp_etype) {
 256                 /* Reset the session ID */
 257                 if (sav->tdb_cryptoid != 0)
 258                         sav->tdb_cryptoid = crp->crp_sid;
 259
 260                 if (crp->crp_etype == EAGAIN) {
 261                         return crypto_dispatch(crp);
 262                 }
 263                 IPCOMPSTAT_INC(ipcomps_noxform);
 264                 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
 265                 error = crp->crp_etype;
 266                 goto bad;
 267         }
 268         /* Shouldn't happen... */
 269         if (m == NULL) {
 270                 IPCOMPSTAT_INC(ipcomps_crypto);
 271                 DPRINTF(("%s: null mbuf returned from crypto\n", __func__));
 272                 error = EINVAL;
 273                 goto bad;
 274         }
 275         IPCOMPSTAT_INC(ipcomps_hist[sav->alg_comp]);
 276
 277         clen = crp->crp_olen;           /* Length of data after processing */
 278
 279         /* Release the crypto descriptors */
 280         free(tc, M_XDATA), tc = NULL;
 281         crypto_freereq(crp), crp = NULL;
 282
 283         /* In case it's not done already, adjust the size of the mbuf chain */
 284         m->m_pkthdr.len = clen + hlen + skip;
 285
 286         if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
 287                 IPCOMPSTAT_INC(ipcomps_hdrops);         /*XXX*/
 288                 DPRINTF(("%s: m_pullup failed\n", __func__));
 289                 error = EINVAL;                         /*XXX*/
 290                 goto bad;
 291         }
 292
 293         /* Keep the next protocol field */
 294         addr = (caddr_t) mtod(m, struct ip *) + skip;
 295         nproto = ((struct ipcomp *) addr)->comp_nxt;
 296
 297         /* Remove the IPCOMP header */
 298         error = m_striphdr(m, skip, hlen);
 299         if (error) {
 300                 IPCOMPSTAT_INC(ipcomps_hdrops);
 301                 DPRINTF(("%s: bad mbuf chain, IPCA %s/%08lx\n", __func__,
 302                     ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
 303                     (u_long) ntohl(sav->spi)));
 304                 goto bad;
 305         }
 306
 307         /* Restore the Next Protocol field */
 308         m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto);
 309
 310         switch (saidx->dst.sa.sa_family) {
 311 #ifdef INET6
 312         case AF_INET6:
 313                 error = ipsec6_common_input_cb(m, sav, skip, protoff);
 314                 break;
 315 #endif
 316 #ifdef INET
 317         case AF_INET:
 318                 error = ipsec4_common_input_cb(m, sav, skip, protoff);
 319                 break;
 320 #endif
 321         default:
 322                 panic("%s: Unexpected address family: %d saidx=%p", __func__,
 323                     saidx->dst.sa.sa_family, saidx);
 324         }
 325
 326         KEY_FREESAV(&sav);
 327         return error;
 328 bad:
 329         if (sav)
 330                 KEY_FREESAV(&sav);
 331         if (m)
 332                 m_freem(m);
 333         if (tc != NULL)
 334                 free(tc, M_XDATA);
 335         if (crp)
 336                 crypto_freereq(crp);
 337         return error;
 338 }
 339
 340 /*
 341  * IPComp output routine, called by ipsec[46]_process_packet()
 342  */
 343 static int
 344 ipcomp_output(struct mbuf *m, struct ipsecrequest *isr, struct mbuf **mp,
 345     int skip, int protoff)
 346 {
 347         char buf[INET6_ADDRSTRLEN];
 348         struct secasvar *sav;
 349         struct comp_algo *ipcompx;
 350         int error, ralen, maxpacketsize;
 351         struct cryptodesc *crdc;
 352         struct cryptop *crp;
 353         struct tdb_crypto *tc;
 354
 355         sav = isr->sav;
 356         IPSEC_ASSERT(sav != NULL, ("null SA"));
 357         ipcompx = sav->tdb_compalgxform;
 358         IPSEC_ASSERT(ipcompx != NULL, ("null compression xform"));
 359
 360         /*
 361          * Do not touch the packet in case our payload to compress
 362          * is lower than the minimal threshold of the compression
 363          * alogrithm.  We will just send out the data uncompressed.
 364          * See RFC 3173, 2.2. Non-Expansion Policy.
 365          */
 366         if (m->m_pkthdr.len <= ipcompx->minlen) {
 367                 IPCOMPSTAT_INC(ipcomps_threshold);
 368                 return ipsec_process_done(m, isr);
 369         }
 370
 371         ralen = m->m_pkthdr.len - skip; /* Raw payload length before comp. */
 372         IPCOMPSTAT_INC(ipcomps_output);
 373
 374         /* Check for maximum packet size violations. */
 375         switch (sav->sah->saidx.dst.sa.sa_family) {
 376 #ifdef INET
 377         case AF_INET:
 378                 maxpacketsize = IP_MAXPACKET;
 379                 break;
 380 #endif /* INET */
 381 #ifdef INET6
 382         case AF_INET6:
 383                 maxpacketsize = IPV6_MAXPACKET;
 384                 break;
 385 #endif /* INET6 */
 386         default:
 387                 IPCOMPSTAT_INC(ipcomps_nopf);
 388                 DPRINTF(("%s: unknown/unsupported protocol family %d, "
 389                     "IPCA %s/%08lx\n", __func__,
 390                     sav->sah->saidx.dst.sa.sa_family,
 391                     ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
 392                     (u_long) ntohl(sav->spi)));
 393                 error = EPFNOSUPPORT;
 394                 goto bad;
 395         }
 396         if (ralen + skip + IPCOMP_HLENGTH > maxpacketsize) {
 397                 IPCOMPSTAT_INC(ipcomps_toobig);
 398                 DPRINTF(("%s: packet in IPCA %s/%08lx got too big "
 399                     "(len %u, max len %u)\n", __func__,
 400                     ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
 401                     (u_long) ntohl(sav->spi),
 402                     ralen + skip + IPCOMP_HLENGTH, maxpacketsize));
 403                 error = EMSGSIZE;
 404                 goto bad;
 405         }
 406
 407         /* Update the counters */
 408         IPCOMPSTAT_ADD(ipcomps_obytes, m->m_pkthdr.len - skip);
 409
 410         m = m_unshare(m, M_NOWAIT);
 411         if (m == NULL) {
 412                 IPCOMPSTAT_INC(ipcomps_hdrops);
 413                 DPRINTF(("%s: cannot clone mbuf chain, IPCA %s/%08lx\n",
 414                     __func__, ipsec_address(&sav->sah->saidx.dst, buf,
 415                     sizeof(buf)), (u_long) ntohl(sav->spi)));
 416                 error = ENOBUFS;
 417                 goto bad;
 418         }
 419
 420         /* Ok now, we can pass to the crypto processing. */
 421
 422         /* Get crypto descriptors */
 423         crp = crypto_getreq(1);
 424         if (crp == NULL) {
 425                 IPCOMPSTAT_INC(ipcomps_crypto);
 426                 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
 427                 error = ENOBUFS;
 428                 goto bad;
 429         }
 430         crdc = crp->crp_desc;
 431
 432         /* Compression descriptor */
 433         crdc->crd_skip = skip;
 434         crdc->crd_len = ralen;
 435         crdc->crd_flags = CRD_F_COMP;
 436         crdc->crd_inject = skip;
 437
 438         /* Compression operation */
 439         crdc->crd_alg = ipcompx->type;
 440
 441         /* IPsec-specific opaque crypto info */
 442         tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
 443                 M_XDATA, M_NOWAIT|M_ZERO);
 444         if (tc == NULL) {
 445                 IPCOMPSTAT_INC(ipcomps_crypto);
 446                 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
 447                 crypto_freereq(crp);
 448                 error = ENOBUFS;
 449                 goto bad;
 450         }
 451
 452         key_addref(isr->sp);
 453         tc->tc_isr = isr;
 454         KEY_ADDREFSA(sav);
 455         tc->tc_sav = sav;
 456         tc->tc_spi = sav->spi;
 457         tc->tc_dst = sav->sah->saidx.dst;
 458         tc->tc_proto = sav->sah->saidx.proto;
 459         tc->tc_protoff = protoff;
 460         tc->tc_skip = skip;
 461
 462         /* Crypto operation descriptor */
 463         crp->crp_ilen = m->m_pkthdr.len;        /* Total input length */
 464         crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
 465         crp->crp_buf = (caddr_t) m;
 466         crp->crp_callback = ipcomp_output_cb;
 467         crp->crp_opaque = (caddr_t) tc;
 468         crp->crp_sid = sav->tdb_cryptoid;
 469
 470         return crypto_dispatch(crp);
 471 bad:
 472         if (m)
 473                 m_freem(m);
 474         return (error);
 475 }
 476
 477 /*
 478  * IPComp output callback from the crypto driver.
 479  */
 480 static int
 481 ipcomp_output_cb(struct cryptop *crp)
 482 {
 483         char buf[INET6_ADDRSTRLEN];
 484         struct tdb_crypto *tc;
 485         struct ipsecrequest *isr;
 486         struct secasvar *sav;
 487         struct mbuf *m;
 488         int error, skip;
 489
 490         tc = (struct tdb_crypto *) crp->crp_opaque;
 491         IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
 492         m = (struct mbuf *) crp->crp_buf;
 493         skip = tc->tc_skip;
 494
 495         isr = tc->tc_isr;
 496         IPSEC_ASSERT(isr->sp != NULL, ("NULL isr->sp"));
 497         IPSECREQUEST_LOCK(isr);
 498         sav = tc->tc_sav;
 499         /* With the isr lock released SA pointer can be updated. */
 500         if (sav != isr->sav) {
 501                 IPCOMPSTAT_INC(ipcomps_notdb);
 502                 DPRINTF(("%s: SA expired while in crypto\n", __func__));
 503                 error = ENOBUFS;                /*XXX*/
 504                 goto bad;
 505         }
 506
 507         /* Check for crypto errors */
 508         if (crp->crp_etype) {
 509                 /* Reset the session ID */
 510                 if (sav->tdb_cryptoid != 0)
 511                         sav->tdb_cryptoid = crp->crp_sid;
 512
 513                 if (crp->crp_etype == EAGAIN) {
 514                         IPSECREQUEST_UNLOCK(isr);
 515                         return crypto_dispatch(crp);
 516                 }
 517                 IPCOMPSTAT_INC(ipcomps_noxform);
 518                 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
 519                 error = crp->crp_etype;
 520                 goto bad;
 521         }
 522         /* Shouldn't happen... */
 523         if (m == NULL) {
 524                 IPCOMPSTAT_INC(ipcomps_crypto);
 525                 DPRINTF(("%s: bogus return buffer from crypto\n", __func__));
 526                 error = EINVAL;
 527                 goto bad;
 528         }
 529         IPCOMPSTAT_INC(ipcomps_hist[sav->alg_comp]);
 530
 531         if (crp->crp_ilen - skip > crp->crp_olen) {
 532                 struct mbuf *mo;
 533                 struct ipcomp *ipcomp;
 534                 int roff;
 535                 uint8_t prot;
 536
 537                 /* Compression helped, inject IPCOMP header. */
 538                 mo = m_makespace(m, skip, IPCOMP_HLENGTH, &roff);
 539                 if (mo == NULL) {
 540                         IPCOMPSTAT_INC(ipcomps_wrap);
 541                         DPRINTF(("%s: IPCOMP header inject failed for IPCA %s/%08lx\n",
 542                             __func__, ipsec_address(&sav->sah->saidx.dst, buf,
 543                             sizeof(buf)), (u_long) ntohl(sav->spi)));
 544                         error = ENOBUFS;
 545                         goto bad;
 546                 }
 547                 ipcomp = (struct ipcomp *)(mtod(mo, caddr_t) + roff);
 548
 549                 /* Initialize the IPCOMP header */
 550                 /* XXX alignment always correct? */
 551                 switch (sav->sah->saidx.dst.sa.sa_family) {
 552 #ifdef INET
 553                 case AF_INET:
 554                         ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p;
 555                         break;
 556 #endif /* INET */
 557 #ifdef INET6
 558                 case AF_INET6:
 559                         ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt;
 560                         break;
 561 #endif
 562                 }
 563                 ipcomp->comp_flags = 0;
 564                 ipcomp->comp_cpi = htons((u_int16_t) ntohl(sav->spi));
 565
 566                 /* Fix Next Protocol in IPv4/IPv6 header */
 567                 prot = IPPROTO_IPCOMP;
 568                 m_copyback(m, tc->tc_protoff, sizeof(u_int8_t),
 569                     (u_char *)&prot);
 570
 571                 /* Adjust the length in the IP header */
 572                 switch (sav->sah->saidx.dst.sa.sa_family) {
 573 #ifdef INET
 574                 case AF_INET:
 575                         mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
 576                         break;
 577 #endif /* INET */
 578 #ifdef INET6
 579                 case AF_INET6:
 580                         mtod(m, struct ip6_hdr *)->ip6_plen =
 581                                 htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr);
 582                         break;
 583 #endif /* INET6 */
 584                 default:
 585                         IPCOMPSTAT_INC(ipcomps_nopf);
 586                         DPRINTF(("%s: unknown/unsupported protocol "
 587                             "family %d, IPCA %s/%08lx\n", __func__,
 588                             sav->sah->saidx.dst.sa.sa_family,
 589                             ipsec_address(&sav->sah->saidx.dst, buf,
 590                                 sizeof(buf)), (u_long) ntohl(sav->spi)));
 591                         error = EPFNOSUPPORT;
 592                         goto bad;
 593                 }
 594         } else {
 595                 /* Compression was useless, we have lost time. */
 596                 IPCOMPSTAT_INC(ipcomps_uncompr);
 597                 DPRINTF(("%s: compressions was useless %d - %d <= %d\n",
 598                     __func__, crp->crp_ilen, skip, crp->crp_olen));
 599                 /* XXX remember state to not compress the next couple
 600                  *     of packets, RFC 3173, 2.2. Non-Expansion Policy */
 601         }
 602
 603         /* Release the crypto descriptor */
 604         free(tc, M_XDATA);
 605         crypto_freereq(crp);
 606
 607         /* NB: m is reclaimed by ipsec_process_done. */
 608         error = ipsec_process_done(m, isr);
 609         KEY_FREESAV(&sav);
 610         IPSECREQUEST_UNLOCK(isr);
 611         KEY_FREESP(&isr->sp);
 612         return (error);
 613 bad:
 614         if (sav)
 615                 KEY_FREESAV(&sav);
 616         IPSECREQUEST_UNLOCK(isr);
 617         KEY_FREESP(&isr->sp);
 618         if (m)
 619                 m_freem(m);
 620         free(tc, M_XDATA);
 621         crypto_freereq(crp);
 622         return (error);
 623 }
 624
 625 static struct xformsw ipcomp_xformsw = {
 626         XF_IPCOMP,              XFT_COMP,               "IPcomp",
 627         ipcomp_init,            ipcomp_zeroize,         ipcomp_input,
 628         ipcomp_output
 629 };
 630
 631 static void
 632 ipcomp_attach(void)
 633 {
 634
 635         xform_register(&ipcomp_xformsw);
 636 }
 637
 638 SYSINIT(ipcomp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipcomp_attach, NULL);