xref: /netbsd-src/sys/netipsec/xform_ipcomp.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: xform_ipcomp.c,v 1.15 2007/09/22 23:33:18 degroote Exp $	*/
2 /*	$FreeBSD: src/sys/netipsec/xform_ipcomp.c,v 1.1.4.1 2003/01/24 05:11:36 sam 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 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: xform_ipcomp.c,v 1.15 2007/09/22 23:33:18 degroote Exp $");
34 
35 /* IP payload compression protocol (IPComp), see RFC 2393 */
36 #include "opt_inet.h"
37 #ifdef __FreeBSD__
38 #include "opt_inet6.h"
39 #endif
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/kernel.h>
46 #include <sys/protosw.h>
47 #include <sys/sysctl.h>
48 
49 #include <netinet/in.h>
50 #include <netinet/in_systm.h>
51 #include <netinet/ip.h>
52 #include <netinet/ip_var.h>
53 
54 #include <net/route.h>
55 #include <netipsec/ipsec.h>
56 #include <netipsec/xform.h>
57 
58 #ifdef INET6
59 #include <netinet/ip6.h>
60 #include <netipsec/ipsec6.h>
61 #endif
62 
63 #include <netipsec/ipcomp.h>
64 #include <netipsec/ipcomp_var.h>
65 
66 #include <netipsec/key.h>
67 #include <netipsec/key_debug.h>
68 
69 #include <netipsec/ipsec_osdep.h>
70 
71 #include <opencrypto/cryptodev.h>
72 #include <opencrypto/deflate.h>
73 #include <opencrypto/xform.h>
74 
75 int	ipcomp_enable = 1;
76 struct	ipcompstat ipcompstat;
77 
78 #ifdef __FreeBSD__
79 SYSCTL_DECL(_net_inet_ipcomp);
80 SYSCTL_INT(_net_inet_ipcomp, OID_AUTO,
81 	ipcomp_enable,	CTLFLAG_RW,	&ipcomp_enable,	0, "");
82 SYSCTL_STRUCT(_net_inet_ipcomp, IPSECCTL_STATS,
83 	stats,		CTLFLAG_RD,	&ipcompstat,	ipcompstat, "");
84 #endif /* __FreeBSD__ */
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(("ipcomp_init: unsupported compression algorithm %d\n",
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, 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 	int hlen = IPCOMP_HLENGTH;
151 
152 	IPSEC_SPLASSERT_SOFTNET("ipcomp_input");
153 
154 	/* Get crypto descriptors */
155 	crp = crypto_getreq(1);
156 	if (crp == NULL) {
157 		m_freem(m);
158 		DPRINTF(("ipcomp_input: no crypto descriptors\n"));
159 		ipcompstat.ipcomps_crypto++;
160 		return ENOBUFS;
161 	}
162 	/* Get IPsec-specific opaque pointer */
163 	tc = (struct tdb_crypto *) malloc(sizeof (*tc), M_XDATA, M_NOWAIT|M_ZERO);
164 	if (tc == NULL) {
165 		m_freem(m);
166 		crypto_freereq(crp);
167 		DPRINTF(("ipcomp_input: cannot allocate tdb_crypto\n"));
168 		ipcompstat.ipcomps_crypto++;
169 		return ENOBUFS;
170 	}
171 	crdc = crp->crp_desc;
172 
173 	crdc->crd_skip = skip + hlen;
174 	crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
175 	crdc->crd_inject = skip;
176 
177 	tc->tc_ptr = 0;
178 
179 	/* Decompression operation */
180 	crdc->crd_alg = sav->tdb_compalgxform->type;
181 
182 	/* Crypto operation descriptor */
183 	crp->crp_ilen = m->m_pkthdr.len - (skip + hlen);
184 	crp->crp_flags = CRYPTO_F_IMBUF;
185 	crp->crp_buf = m;
186 	crp->crp_callback = ipcomp_input_cb;
187 	crp->crp_sid = sav->tdb_cryptoid;
188 	crp->crp_opaque = tc;
189 
190 	/* These are passed as-is to the callback */
191 	tc->tc_spi = sav->spi;
192 	tc->tc_dst = sav->sah->saidx.dst;
193 	tc->tc_proto = sav->sah->saidx.proto;
194 	tc->tc_protoff = protoff;
195 	tc->tc_skip = skip;
196 
197 	return crypto_dispatch(crp);
198 }
199 
200 #ifdef INET6
201 #define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {		     \
202 	if (saidx->dst.sa.sa_family == AF_INET6) {			     \
203 		error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
204 	} else {							     \
205 		error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
206 	}								     \
207 } while (0)
208 #else
209 #define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)		     \
210 	(error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
211 #endif
212 
213 /*
214  * IPComp input callback from the crypto driver.
215  */
216 static int
217 ipcomp_input_cb(struct cryptop *crp)
218 {
219 	struct cryptodesc *crd;
220 	struct tdb_crypto *tc;
221 	int skip, protoff;
222 	struct mtag *mtag;
223 	struct mbuf *m;
224 	struct secasvar *sav;
225 	struct secasindex *saidx;
226 	int s, hlen = IPCOMP_HLENGTH, error, clen;
227 	u_int8_t nproto;
228 	void *addr;
229 	u_int16_t dport = 0;
230 	u_int16_t sport = 0;
231 #ifdef IPSEC_NAT_T
232 	struct m_tag * tag = NULL;
233 #endif
234 
235 	crd = crp->crp_desc;
236 
237 	tc = (struct tdb_crypto *) crp->crp_opaque;
238 	IPSEC_ASSERT(tc != NULL, ("ipcomp_input_cb: null opaque crypto data area!"));
239 	skip = tc->tc_skip;
240 	protoff = tc->tc_protoff;
241 	mtag = (struct mtag *) tc->tc_ptr;
242 	m = (struct mbuf *) crp->crp_buf;
243 
244 #ifdef IPSEC_NAT_T
245 	/* find the source port for NAT-T */
246 	if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) {
247 		sport = ((u_int16_t *)(tag + 1))[0];
248 		dport = ((u_int16_t *)(tag + 1))[1];
249 	}
250 #endif
251 
252 	s = splsoftnet();
253 
254 	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport);
255 	if (sav == NULL) {
256 		ipcompstat.ipcomps_notdb++;
257 		DPRINTF(("ipcomp_input_cb: SA expired while in crypto\n"));
258 		error = ENOBUFS;		/*XXX*/
259 		goto bad;
260 	}
261 
262 	saidx = &sav->sah->saidx;
263 	IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
264 		saidx->dst.sa.sa_family == AF_INET6,
265 		("ah_input_cb: unexpected protocol family %u",
266 		 saidx->dst.sa.sa_family));
267 
268 	/* Check for crypto errors */
269 	if (crp->crp_etype) {
270 		/* Reset the session ID */
271 		if (sav->tdb_cryptoid != 0)
272 			sav->tdb_cryptoid = crp->crp_sid;
273 
274 		if (crp->crp_etype == EAGAIN) {
275 			KEY_FREESAV(&sav);
276 			splx(s);
277 			return crypto_dispatch(crp);
278 		}
279 
280 		ipcompstat.ipcomps_noxform++;
281 		DPRINTF(("ipcomp_input_cb: crypto error %d\n", crp->crp_etype));
282 		error = crp->crp_etype;
283 		goto bad;
284 	}
285 	/* Shouldn't happen... */
286 	if (m == NULL) {
287 		ipcompstat.ipcomps_crypto++;
288 		DPRINTF(("ipcomp_input_cb: null mbuf returned from crypto\n"));
289 		error = EINVAL;
290 		goto bad;
291 	}
292 	ipcompstat.ipcomps_hist[sav->alg_comp]++;
293 
294 	clen = crp->crp_olen;		/* Length of data after processing */
295 
296 	/* Release the crypto descriptors */
297 	free(tc, M_XDATA), tc = NULL;
298 	crypto_freereq(crp), crp = NULL;
299 
300 	/* In case it's not done already, adjust the size of the mbuf chain */
301 	m->m_pkthdr.len = clen + hlen + skip;
302 
303 	if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
304 		ipcompstat.ipcomps_hdrops++;		/*XXX*/
305 		DPRINTF(("ipcomp_input_cb: m_pullup failed\n"));
306 		error = EINVAL;				/*XXX*/
307 		goto bad;
308 	}
309 
310 	/* Keep the next protocol field */
311 	addr = (uint8_t*) mtod(m, struct ip *) + skip;
312 	nproto = ((struct ipcomp *) addr)->comp_nxt;
313 
314 	/* Remove the IPCOMP header */
315 	error = m_striphdr(m, skip, hlen);
316 	if (error) {
317 		ipcompstat.ipcomps_hdrops++;
318 		DPRINTF(("ipcomp_input_cb: bad mbuf chain, IPCA %s/%08lx\n",
319 			 ipsec_address(&sav->sah->saidx.dst),
320 			 (u_long) ntohl(sav->spi)));
321 		goto bad;
322 	}
323 
324 	/* Restore the Next Protocol field */
325 	m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto);
326 
327 	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, NULL);
328 
329 	KEY_FREESAV(&sav);
330 	splx(s);
331 	return error;
332 bad:
333 	if (sav)
334 		KEY_FREESAV(&sav);
335 	splx(s);
336 	if (m)
337 		m_freem(m);
338 	if (tc != NULL)
339 		free(tc, M_XDATA);
340 	if (crp)
341 		crypto_freereq(crp);
342 	return error;
343 }
344 
345 /*
346  * IPComp output routine, called by ipsec[46]_process_packet()
347  */
348 static int
349 ipcomp_output(
350     struct mbuf *m,
351     struct ipsecrequest *isr,
352     struct mbuf **mp,
353     int skip,
354     int protoff
355 )
356 {
357 	struct secasvar *sav;
358 	struct comp_algo *ipcompx;
359 	int error, ralen, hlen, maxpacketsize;
360 	struct cryptodesc *crdc;
361 	struct cryptop *crp;
362 	struct tdb_crypto *tc;
363 
364 	IPSEC_SPLASSERT_SOFTNET("ipcomp_output");
365 	sav = isr->sav;
366 	IPSEC_ASSERT(sav != NULL, ("ipcomp_output: null SA"));
367 	ipcompx = sav->tdb_compalgxform;
368 	IPSEC_ASSERT(ipcompx != NULL, ("ipcomp_output: null compression xform"));
369 
370 	ralen = m->m_pkthdr.len - skip;	/* Raw payload length before comp. */
371 
372     /* Don't process the packet if it is too short */
373 	if (ralen < ipcompx->minlen) {
374 		ipcompstat.ipcomps_minlen++;
375 		return ipsec_process_done(m,isr);
376 	}
377 
378 	hlen = IPCOMP_HLENGTH;
379 
380 	ipcompstat.ipcomps_output++;
381 
382 	/* Check for maximum packet size violations. */
383 	switch (sav->sah->saidx.dst.sa.sa_family) {
384 #ifdef INET
385 	case AF_INET:
386 		maxpacketsize =  IP_MAXPACKET;
387 		break;
388 #endif /* INET */
389 #ifdef INET6
390 	case AF_INET6:
391 		maxpacketsize =  IPV6_MAXPACKET;
392 		break;
393 #endif /* INET6 */
394 	default:
395 		ipcompstat.ipcomps_nopf++;
396 		DPRINTF(("ipcomp_output: unknown/unsupported protocol family %d"
397 		    ", IPCA %s/%08lx\n",
398 		    sav->sah->saidx.dst.sa.sa_family,
399 		    ipsec_address(&sav->sah->saidx.dst),
400 		    (u_long) ntohl(sav->spi)));
401 		error = EPFNOSUPPORT;
402 		goto bad;
403 	}
404 	if (skip + hlen + ralen > maxpacketsize) {
405 		ipcompstat.ipcomps_toobig++;
406 		DPRINTF(("ipcomp_output: packet in IPCA %s/%08lx got too big "
407 		    "(len %u, max len %u)\n",
408 		    ipsec_address(&sav->sah->saidx.dst),
409 		    (u_long) ntohl(sav->spi),
410 		    skip + hlen + ralen, maxpacketsize));
411 		error = EMSGSIZE;
412 		goto bad;
413 	}
414 
415 	/* Update the counters */
416 	ipcompstat.ipcomps_obytes += m->m_pkthdr.len - skip;
417 
418 	m = m_clone(m);
419 	if (m == NULL) {
420 		ipcompstat.ipcomps_hdrops++;
421 		DPRINTF(("ipcomp_output: cannot clone mbuf chain, IPCA %s/%08lx\n",
422 		    ipsec_address(&sav->sah->saidx.dst),
423 		    (u_long) ntohl(sav->spi)));
424 		error = ENOBUFS;
425 		goto bad;
426 	}
427 
428 	/* Ok now, we can pass to the crypto processing */
429 
430 	/* Get crypto descriptors */
431 	crp = crypto_getreq(1);
432 	if (crp == NULL) {
433 		ipcompstat.ipcomps_crypto++;
434 		DPRINTF(("ipcomp_output: failed to acquire crypto descriptor\n"));
435 		error = ENOBUFS;
436 		goto bad;
437 	}
438 	crdc = crp->crp_desc;
439 
440 	/* Compression descriptor */
441 	crdc->crd_skip = skip;
442 	crdc->crd_len = m->m_pkthdr.len - skip;
443 	crdc->crd_flags = CRD_F_COMP;
444 	crdc->crd_inject = skip;
445 
446 	/* Compression operation */
447 	crdc->crd_alg = ipcompx->type;
448 
449 	/* IPsec-specific opaque crypto info */
450 	tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
451 		M_XDATA, M_NOWAIT|M_ZERO);
452 	if (tc == NULL) {
453 		ipcompstat.ipcomps_crypto++;
454 		DPRINTF(("ipcomp_output: failed to allocate tdb_crypto\n"));
455 		crypto_freereq(crp);
456 		error = ENOBUFS;
457 		goto bad;
458 	}
459 
460 	tc->tc_isr = isr;
461 	tc->tc_spi = sav->spi;
462 	tc->tc_dst = sav->sah->saidx.dst;
463 	tc->tc_proto = sav->sah->saidx.proto;
464 	tc->tc_skip = skip;
465 	tc->tc_protoff = protoff;
466 
467 	/* Crypto operation descriptor */
468 	crp->crp_ilen = m->m_pkthdr.len;	/* Total input length */
469 	crp->crp_flags = CRYPTO_F_IMBUF;
470 	crp->crp_buf = m;
471 	crp->crp_callback = ipcomp_output_cb;
472 	crp->crp_opaque = tc;
473 	crp->crp_sid = sav->tdb_cryptoid;
474 
475 	return crypto_dispatch(crp);
476 bad:
477 	if (m)
478 		m_freem(m);
479 	return (error);
480 }
481 
482 /*
483  * IPComp output callback from the crypto driver.
484  */
485 static int
486 ipcomp_output_cb(struct cryptop *crp)
487 {
488 	struct tdb_crypto *tc;
489 	struct ipsecrequest *isr;
490 	struct secasvar *sav;
491 	struct mbuf *m, *mo;
492 	int s, error, skip, rlen, roff;
493 	u_int8_t prot;
494 	u_int16_t cpi;
495 	struct ipcomp * ipcomp;
496 
497 
498 	tc = (struct tdb_crypto *) crp->crp_opaque;
499 	IPSEC_ASSERT(tc != NULL, ("ipcomp_output_cb: null opaque data area!"));
500 	m = (struct mbuf *) crp->crp_buf;
501 	skip = tc->tc_skip;
502 	rlen = crp->crp_ilen - skip;
503 
504 	s = splsoftnet();
505 
506 	isr = tc->tc_isr;
507 	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0);
508 	if (sav == NULL) {
509 		ipcompstat.ipcomps_notdb++;
510 		DPRINTF(("ipcomp_output_cb: SA expired while in crypto\n"));
511 		error = ENOBUFS;		/*XXX*/
512 		goto bad;
513 	}
514 	IPSEC_ASSERT(isr->sav == sav, ("ipcomp_output_cb: SA changed\n"));
515 
516 	/* Check for crypto errors */
517 	if (crp->crp_etype) {
518 		/* Reset session ID */
519 		if (sav->tdb_cryptoid != 0)
520 			sav->tdb_cryptoid = crp->crp_sid;
521 
522 		if (crp->crp_etype == EAGAIN) {
523 			KEY_FREESAV(&sav);
524 			splx(s);
525 			return crypto_dispatch(crp);
526 		}
527 		ipcompstat.ipcomps_noxform++;
528 		DPRINTF(("ipcomp_output_cb: crypto error %d\n", crp->crp_etype));
529 		error = crp->crp_etype;
530 		goto bad;
531 	}
532 	/* Shouldn't happen... */
533 	if (m == NULL) {
534 		ipcompstat.ipcomps_crypto++;
535 		DPRINTF(("ipcomp_output_cb: bogus return buffer from crypto\n"));
536 		error = EINVAL;
537 		goto bad;
538 	}
539 	ipcompstat.ipcomps_hist[sav->alg_comp]++;
540 
541 	if (rlen > crp->crp_olen) {
542 		/* Inject IPCOMP header */
543 		mo = m_makespace(m, skip, IPCOMP_HLENGTH, &roff);
544 		if (mo == NULL) {
545 			ipcompstat.ipcomps_wrap++;
546 			DPRINTF(("ipcomp_output: failed to inject IPCOMP header for "
547 					 "IPCA %s/%08lx\n",
548 						ipsec_address(&sav->sah->saidx.dst),
549 						(u_long) ntohl(sav->spi)));
550 			error = ENOBUFS;
551 			goto bad;
552 		}
553 		ipcomp = (struct ipcomp *)(mtod(mo, char *) + roff);
554 
555 		/* Initialize the IPCOMP header */
556 		/* XXX alignment always correct? */
557 		switch (sav->sah->saidx.dst.sa.sa_family) {
558 #ifdef INET
559 		case AF_INET:
560 			ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p;
561 			 break;
562 #endif /* INET */
563 #ifdef INET6
564 		case AF_INET6:
565 			ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt;
566 		break;
567 #endif
568 		}
569 		ipcomp->comp_flags = 0;
570 
571 		if ((sav->flags & SADB_X_EXT_RAWCPI) == 0)
572 			 cpi = sav->alg_enc;
573 		else
574 			cpi = ntohl(sav->spi) & 0xffff;
575 		ipcomp->comp_cpi = htons(cpi);
576 
577 		/* Fix Next Protocol in IPv4/IPv6 header */
578 		prot = IPPROTO_IPCOMP;
579 		m_copyback(m, tc->tc_protoff, sizeof(u_int8_t), (u_char *)&prot);
580 
581 		/* Adjust the length in the IP header */
582 		switch (sav->sah->saidx.dst.sa.sa_family) {
583 #ifdef INET
584 		case AF_INET:
585 			mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
586 			break;
587 #endif /* INET */
588 #ifdef INET6
589 		case AF_INET6:
590 			mtod(m, struct ip6_hdr *)->ip6_plen =
591 				htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr);
592 			break;
593 #endif /* INET6 */
594 		default:
595 			ipcompstat.ipcomps_nopf++;
596 			DPRINTF(("ipcomp_output: unknown/unsupported protocol "
597 			    "family %d, IPCA %s/%08lx\n",
598 			    sav->sah->saidx.dst.sa.sa_family,
599 			    ipsec_address(&sav->sah->saidx.dst),
600 			    (u_long) ntohl(sav->spi)));
601 			error = EPFNOSUPPORT;
602 			goto bad;
603 		}
604 	} else {
605 		/* compression was useless, we have lost time */
606 		/* XXX add statistic */
607 	}
608 
609 	/* Release the crypto descriptor */
610 	free(tc, M_XDATA);
611 	crypto_freereq(crp);
612 
613 	/* NB: m is reclaimed by ipsec_process_done. */
614 	error = ipsec_process_done(m, isr);
615 	KEY_FREESAV(&sav);
616 	splx(s);
617 	return error;
618 bad:
619 	if (sav)
620 		KEY_FREESAV(&sav);
621 	splx(s);
622 	if (m)
623 		m_freem(m);
624 	free(tc, M_XDATA);
625 	crypto_freereq(crp);
626 	return error;
627 }
628 
629 static struct xformsw ipcomp_xformsw = {
630 	XF_IPCOMP,		XFT_COMP,		"IPcomp",
631 	ipcomp_init,		ipcomp_zeroize,		ipcomp_input,
632 	ipcomp_output,
633 	NULL,
634 };
635 
636 INITFN void
637 ipcomp_attach(void)
638 {
639 	xform_register(&ipcomp_xformsw);
640 }
641 
642 #ifdef __FreeBSD__
643 SYSINIT(ipcomp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, ipcomp_attach, NULL)
644 #endif /* __FreeBSD__ */
645