kernel - MFC an IPSEC security fix related to nested compressed frames
[dragonfly.git] / 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 1.10 2006/10/12 01:32:51 hsu 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 #include <sys/thread2.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 <netproto/ipsec/ipsec.h>
52 #include <netproto/ipsec/xform.h>
53
54 #ifdef INET6
55 #include <netinet/ip6.h>
56 #include <netproto/ipsec/ipsec6.h>
57 #endif
58
59 #include <netproto/ipsec/ipcomp.h>
60 #include <netproto/ipsec/ipcomp_var.h>
61
62 #include <netproto/ipsec/key.h>
63 #include <netproto/ipsec/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(("ipcomp_init: unsupported compression algorithm %d\n",
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         struct ipcomp *ipcomp;
143         caddr_t addr;
144         int hlen = IPCOMP_HLENGTH;
145
146         /*
147          * Check that the next header of the IPComp is not IPComp again, before
148          * doing any real work.  Given it is not possible to do double
149          * compression it means someone is playing tricks on us.
150          */
151         if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == NULL) {
152                 ipcompstat.ipcomps_hdrops++;            /*XXX*/
153                 DPRINTF(("%s: m_pullup failed\n", __func__));
154                 return (ENOBUFS);
155         }
156         addr = (caddr_t) mtod(m, struct ip *) + skip;
157         ipcomp = (struct ipcomp *)addr;
158         if (ipcomp->comp_nxt == IPPROTO_IPCOMP) {
159                 m_freem(m);
160                 ipcompstat.ipcomps_pdrops++;    /* XXX have our own stats? */
161                 DPRINTF(("%s: recursive compression detected\n", __func__));
162                 return (EINVAL);
163         }
164
165         /* Get crypto descriptors */
166         crp = crypto_getreq(1);
167         if (crp == NULL) {
168                 m_freem(m);
169                 DPRINTF(("ipcomp_input: no crypto descriptors\n"));
170                 ipcompstat.ipcomps_crypto++;
171                 return ENOBUFS;
172         }
173         /* Get IPsec-specific opaque pointer */
174         tc = kmalloc(sizeof (*tc), M_XDATA, 
175                     M_INTWAIT | M_ZERO | M_NULLOK);
176         if (tc == NULL) {
177                 m_freem(m);
178                 crypto_freereq(crp);
179                 DPRINTF(("ipcomp_input: cannot allocate tdb_crypto\n"));
180                 ipcompstat.ipcomps_crypto++;
181                 return ENOBUFS;
182         }
183         crdc = crp->crp_desc;
184
185         crdc->crd_skip = skip + hlen;
186         crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
187         crdc->crd_inject = skip;
188
189         tc->tc_ptr = 0;
190
191         /* Decompression operation */
192         crdc->crd_alg = sav->tdb_compalgxform->type;
193
194         /* Crypto operation descriptor */
195         crp->crp_ilen = m->m_pkthdr.len - (skip + hlen);
196         crp->crp_flags = CRYPTO_F_IMBUF;
197         crp->crp_buf = (caddr_t) m;
198         crp->crp_callback = ipcomp_input_cb;
199         crp->crp_sid = sav->tdb_cryptoid;
200         crp->crp_opaque = (caddr_t) tc;
201
202         /* These are passed as-is to the callback */
203         tc->tc_spi = sav->spi;
204         tc->tc_dst = sav->sah->saidx.dst;
205         tc->tc_proto = sav->sah->saidx.proto;
206         tc->tc_protoff = protoff;
207         tc->tc_skip = skip;
208
209         return crypto_dispatch(crp);
210 }
211
212 #ifdef INET6
213 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {              \
214         if (saidx->dst.sa.sa_family == AF_INET6) {                           \
215                 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
216         } else {                                                             \
217                 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
218         }                                                                    \
219 } while (0)
220 #else
221 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)                   \
222         (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
223 #endif
224
225 /*
226  * IPComp input callback from the crypto driver.
227  */
228 static int
229 ipcomp_input_cb(struct cryptop *crp)
230 {
231         struct cryptodesc *crd;
232         struct tdb_crypto *tc;
233         int skip, protoff;
234         struct mtag *mtag;
235         struct mbuf *m;
236         struct secasvar *sav;
237         struct secasindex *saidx;
238         int hlen = IPCOMP_HLENGTH, error, clen;
239         u_int8_t nproto;
240         caddr_t addr;
241
242         crd = crp->crp_desc;
243
244         tc = (struct tdb_crypto *) crp->crp_opaque;
245         KASSERT(tc != NULL, ("ipcomp_input_cb: null opaque crypto data area!"));
246         skip = tc->tc_skip;
247         protoff = tc->tc_protoff;
248         mtag = (struct mtag *) tc->tc_ptr;
249         m = (struct mbuf *) crp->crp_buf;
250
251         crit_enter();
252
253         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
254         if (sav == NULL) {
255                 ipcompstat.ipcomps_notdb++;
256                 DPRINTF(("ipcomp_input_cb: SA expired while in crypto\n"));
257                 error = ENOBUFS;                /*XXX*/
258                 goto bad;
259         }
260
261         saidx = &sav->sah->saidx;
262         KASSERT(saidx->dst.sa.sa_family == AF_INET ||
263                 saidx->dst.sa.sa_family == AF_INET6,
264                 ("ah_input_cb: unexpected protocol family %u",
265                  saidx->dst.sa.sa_family));
266
267         /* Check for crypto errors */
268         if (crp->crp_etype) {
269                 /* Reset the session ID */
270                 if (sav->tdb_cryptoid != 0)
271                         sav->tdb_cryptoid = crp->crp_sid;
272
273                 if (crp->crp_etype == EAGAIN) {
274                         KEY_FREESAV(&sav);
275                         crit_exit();
276                         return crypto_dispatch(crp);
277                 }
278
279                 ipcompstat.ipcomps_noxform++;
280                 DPRINTF(("ipcomp_input_cb: crypto error %d\n", crp->crp_etype));
281                 error = crp->crp_etype;
282                 goto bad;
283         }
284         /* Shouldn't happen... */
285         if (m == NULL) {
286                 ipcompstat.ipcomps_crypto++;
287                 DPRINTF(("ipcomp_input_cb: null mbuf returned from crypto\n"));
288                 error = EINVAL;
289                 goto bad;
290         }
291         ipcompstat.ipcomps_hist[sav->alg_comp]++;
292
293         clen = crp->crp_olen;           /* Length of data after processing */
294
295         /* Release the crypto descriptors */
296         kfree(tc, M_XDATA), tc = NULL;
297         crypto_freereq(crp), crp = NULL;
298
299         /* In case it's not done already, adjust the size of the mbuf chain */
300         m->m_pkthdr.len = clen + hlen + skip;
301
302         if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
303                 ipcompstat.ipcomps_hdrops++;            /*XXX*/
304                 DPRINTF(("ipcomp_input_cb: m_pullup failed\n"));
305                 error = EINVAL;                         /*XXX*/
306                 goto bad;
307         }
308
309         /* Keep the next protocol field */
310         addr = (caddr_t) mtod(m, struct ip *) + skip;
311         nproto = ((struct ipcomp *) addr)->comp_nxt;
312
313         /* Remove the IPCOMP header */
314         error = m_striphdr(m, skip, hlen);
315         if (error) {
316                 ipcompstat.ipcomps_hdrops++;
317                 DPRINTF(("ipcomp_input_cb: bad mbuf chain, IPCA %s/%08lx\n",
318                          ipsec_address(&sav->sah->saidx.dst),
319                          (u_long) ntohl(sav->spi)));
320                 goto bad;
321         }
322
323         /* Restore the Next Protocol field */
324         m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto);
325
326         IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, NULL);
327
328         KEY_FREESAV(&sav);
329         crit_exit();
330         return error;
331 bad:
332         if (sav)
333                 KEY_FREESAV(&sav);
334         crit_exit();
335         if (m)
336                 m_freem(m);
337         if (tc != NULL)
338                 kfree(tc, M_XDATA);
339         if (crp)
340                 crypto_freereq(crp);
341         return error;
342 }
343
344 /*
345  * IPComp output routine, called by ipsec[46]_process_packet()
346  */
347 static int
348 ipcomp_output(
349         struct mbuf *m,
350         struct ipsecrequest *isr,
351         struct mbuf **mp,
352         int skip,
353         int protoff
354 )
355 {
356         struct secasvar *sav;
357         struct comp_algo *ipcompx;
358         int error, ralen, hlen, maxpacketsize, roff;
359         u_int8_t prot;
360         struct cryptodesc *crdc;
361         struct cryptop *crp;
362         struct tdb_crypto *tc;
363         struct mbuf *mo;
364         struct ipcomp *ipcomp;
365
366         sav = isr->sav;
367         KASSERT(sav != NULL, ("ipcomp_output: null SA"));
368         ipcompx = sav->tdb_compalgxform;
369         KASSERT(ipcompx != NULL, ("ipcomp_output: null compression xform"));
370
371         ralen = m->m_pkthdr.len - skip; /* Raw payload length before comp. */
372         hlen = IPCOMP_HLENGTH;
373
374         ipcompstat.ipcomps_output++;
375
376         /* Check for maximum packet size violations. */
377         switch (sav->sah->saidx.dst.sa.sa_family) {
378 #ifdef INET
379         case AF_INET:
380                 maxpacketsize =  IP_MAXPACKET;
381                 break;
382 #endif /* INET */
383 #ifdef INET6
384         case AF_INET6:
385                 maxpacketsize =  IPV6_MAXPACKET;
386                 break;
387 #endif /* INET6 */
388         default:
389                 ipcompstat.ipcomps_nopf++;
390                 DPRINTF(("ipcomp_output: unknown/unsupported protocol family %d"
391                     ", IPCA %s/%08lx\n", 
392                     sav->sah->saidx.dst.sa.sa_family,
393                     ipsec_address(&sav->sah->saidx.dst),
394                     (u_long) ntohl(sav->spi)));
395                 error = EPFNOSUPPORT;
396                 goto bad;
397         }
398         if (skip + hlen + ralen > maxpacketsize) {
399                 ipcompstat.ipcomps_toobig++;
400                 DPRINTF(("ipcomp_output: packet in IPCA %s/%08lx got too big "
401                     "(len %u, max len %u)\n",
402                     ipsec_address(&sav->sah->saidx.dst),
403                     (u_long) ntohl(sav->spi),
404                     skip + hlen + ralen, maxpacketsize));
405                 error = EMSGSIZE;
406                 goto bad;
407         }
408
409         /* Update the counters */
410         ipcompstat.ipcomps_obytes += m->m_pkthdr.len - skip;
411
412         m = m_clone(m);
413         if (m == NULL) {
414                 ipcompstat.ipcomps_hdrops++;
415                 DPRINTF(("ipcomp_output: cannot clone mbuf chain, IPCA %s/%08lx\n", 
416                     ipsec_address(&sav->sah->saidx.dst),
417                     (u_long) ntohl(sav->spi)));
418                 error = ENOBUFS;
419                 goto bad;
420         }
421
422         /* Inject IPCOMP header */
423         mo = m_makespace(m, skip, hlen, &roff);
424         if (mo == NULL) {
425                 ipcompstat.ipcomps_wrap++;
426                 DPRINTF(("ipcomp_output: failed to inject IPCOMP header for "
427                     "IPCA %s/%08lx\n",
428                     ipsec_address(&sav->sah->saidx.dst),
429                     (u_long) ntohl(sav->spi)));
430                 error = ENOBUFS;
431                 goto bad;
432         }
433         ipcomp = (struct ipcomp *)(mtod(mo, caddr_t) + roff);
434
435         /* Initialize the IPCOMP header */
436         /* XXX alignment always correct? */
437         switch (sav->sah->saidx.dst.sa.sa_family) {
438 #ifdef INET
439         case AF_INET:
440                 ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p;
441                 break;
442 #endif /* INET */
443 #ifdef INET6
444         case AF_INET6:
445                 ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt;
446                 break;
447 #endif
448         }
449         ipcomp->comp_flags = 0;
450         ipcomp->comp_cpi = htons((u_int16_t) ntohl(sav->spi));
451
452         /* Fix Next Protocol in IPv4/IPv6 header */
453         prot = IPPROTO_IPCOMP;
454         m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
455
456         /* Ok now, we can pass to the crypto processing */
457
458         /* Get crypto descriptors */
459         crp = crypto_getreq(1);
460         if (crp == NULL) {
461                 ipcompstat.ipcomps_crypto++;
462                 DPRINTF(("ipcomp_output: failed to acquire crypto descriptor\n"));
463                 error = ENOBUFS;
464                 goto bad;
465         }
466         crdc = crp->crp_desc;
467
468         /* Compression descriptor */
469         crdc->crd_skip = skip + hlen;
470         crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
471         crdc->crd_flags = CRD_F_COMP;
472         crdc->crd_inject = skip + hlen;
473
474         /* Compression operation */
475         crdc->crd_alg = ipcompx->type;
476
477         /* IPsec-specific opaque crypto info */
478         tc = kmalloc(sizeof(struct tdb_crypto),
479                     M_XDATA, M_INTWAIT | M_ZERO | M_NULLOK);
480         if (tc == NULL) {
481                 ipcompstat.ipcomps_crypto++;
482                 DPRINTF(("ipcomp_output: failed to allocate tdb_crypto\n"));
483                 crypto_freereq(crp);
484                 error = ENOBUFS;
485                 goto bad;
486         }
487
488         tc->tc_isr = isr;
489         tc->tc_spi = sav->spi;
490         tc->tc_dst = sav->sah->saidx.dst;
491         tc->tc_proto = sav->sah->saidx.proto;
492         tc->tc_skip = skip + hlen;
493
494         /* Crypto operation descriptor */
495         crp->crp_ilen = m->m_pkthdr.len;        /* Total input length */
496         crp->crp_flags = CRYPTO_F_IMBUF;
497         crp->crp_buf = (caddr_t) m;
498         crp->crp_callback = ipcomp_output_cb;
499         crp->crp_opaque = (caddr_t) tc;
500         crp->crp_sid = sav->tdb_cryptoid;
501
502         return crypto_dispatch(crp);
503 bad:
504         if (m)
505                 m_freem(m);
506         return (error);
507 }
508
509 /*
510  * IPComp output callback from the crypto driver.
511  */
512 static int
513 ipcomp_output_cb(struct cryptop *crp)
514 {
515         struct tdb_crypto *tc;
516         struct ipsecrequest *isr;
517         struct secasvar *sav;
518         struct mbuf *m;
519         int error, skip, rlen;
520
521         tc = (struct tdb_crypto *) crp->crp_opaque;
522         KASSERT(tc != NULL, ("ipcomp_output_cb: null opaque data area!"));
523         m = (struct mbuf *) crp->crp_buf;
524         skip = tc->tc_skip;
525         rlen = crp->crp_ilen - skip;
526
527         crit_enter();
528
529         isr = tc->tc_isr;
530         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
531         if (sav == NULL) {
532                 ipcompstat.ipcomps_notdb++;
533                 DPRINTF(("ipcomp_output_cb: SA expired while in crypto\n"));
534                 error = ENOBUFS;                /*XXX*/
535                 goto bad;
536         }
537         KASSERT(isr->sav == sav, ("ipcomp_output_cb: SA changed\n"));
538
539         /* Check for crypto errors */
540         if (crp->crp_etype) {
541                 /* Reset session ID */
542                 if (sav->tdb_cryptoid != 0)
543                         sav->tdb_cryptoid = crp->crp_sid;
544
545                 if (crp->crp_etype == EAGAIN) {
546                         KEY_FREESAV(&sav);
547                         crit_exit();
548                         return crypto_dispatch(crp);
549                 }
550                 ipcompstat.ipcomps_noxform++;
551                 DPRINTF(("ipcomp_output_cb: crypto error %d\n", crp->crp_etype));
552                 error = crp->crp_etype;
553                 goto bad;
554         }
555         /* Shouldn't happen... */
556         if (m == NULL) {
557                 ipcompstat.ipcomps_crypto++;
558                 DPRINTF(("ipcomp_output_cb: bogus return buffer from crypto\n"));
559                 error = EINVAL;
560                 goto bad;
561         }
562         ipcompstat.ipcomps_hist[sav->alg_comp]++;
563
564         if (rlen > crp->crp_olen) {
565                 /* Adjust the length in the IP header */
566                 switch (sav->sah->saidx.dst.sa.sa_family) {
567 #ifdef INET
568                 case AF_INET:
569                         mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
570                         break;
571 #endif /* INET */
572 #ifdef INET6
573                 case AF_INET6:
574                         mtod(m, struct ip6_hdr *)->ip6_plen =
575                                 htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr);
576                         break;
577 #endif /* INET6 */
578                 default:
579                         ipcompstat.ipcomps_nopf++;
580                         DPRINTF(("ipcomp_output: unknown/unsupported protocol "
581                             "family %d, IPCA %s/%08lx\n", 
582                             sav->sah->saidx.dst.sa.sa_family,
583                             ipsec_address(&sav->sah->saidx.dst), 
584                             (u_long) ntohl(sav->spi)));
585                         error = EPFNOSUPPORT;
586                         goto bad;
587                 }
588         } else {
589                 /* compression was useless, we have lost time */
590                 /* XXX add statistic */
591         }
592
593         /* Release the crypto descriptor */
594         kfree(tc, M_XDATA);
595         crypto_freereq(crp);
596
597         /* NB: m is reclaimed by ipsec_process_done. */
598         error = ipsec_process_done(m, isr);
599         KEY_FREESAV(&sav);
600         crit_exit();
601         return error;
602 bad:
603         if (sav)
604                 KEY_FREESAV(&sav);
605         crit_exit();
606         if (m)
607                 m_freem(m);
608         kfree(tc, M_XDATA);
609         crypto_freereq(crp);
610         return error;
611 }
612
613 static struct xformsw ipcomp_xformsw = {
614         XF_IPCOMP,              XFT_COMP,               "IPcomp",
615         ipcomp_init,            ipcomp_zeroize,         ipcomp_input,
616         ipcomp_output
617 };
618
619 static void
620 ipcomp_attach(void)
621 {
622         xform_register(&ipcomp_xformsw);
623 }
624 SYSINIT(ipcomp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, ipcomp_attach, NULL)