xref: /freebsd/sys/netipsec/xform_ipcomp.c (revision bbb29a3c0f2c4565eff6fda70426807b6ed97f8b)
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 	struct cryptodesc *crd;
228 	struct tdb_crypto *tc;
229 	int skip, protoff;
230 	struct mtag *mtag;
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 	mtag = (struct mtag *) tc->tc_ptr;
245 	m = (struct mbuf *) crp->crp_buf;
246 
247 	sav = tc->tc_sav;
248 	IPSEC_ASSERT(sav != NULL, ("null SA!"));
249 
250 	saidx = &sav->sah->saidx;
251 	IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
252 		saidx->dst.sa.sa_family == AF_INET6,
253 		("unexpected protocol family %u", saidx->dst.sa.sa_family));
254 
255 	/* Check for crypto errors */
256 	if (crp->crp_etype) {
257 		/* Reset the session ID */
258 		if (sav->tdb_cryptoid != 0)
259 			sav->tdb_cryptoid = crp->crp_sid;
260 
261 		if (crp->crp_etype == EAGAIN) {
262 			return crypto_dispatch(crp);
263 		}
264 		IPCOMPSTAT_INC(ipcomps_noxform);
265 		DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
266 		error = crp->crp_etype;
267 		goto bad;
268 	}
269 	/* Shouldn't happen... */
270 	if (m == NULL) {
271 		IPCOMPSTAT_INC(ipcomps_crypto);
272 		DPRINTF(("%s: null mbuf returned from crypto\n", __func__));
273 		error = EINVAL;
274 		goto bad;
275 	}
276 	IPCOMPSTAT_INC(ipcomps_hist[sav->alg_comp]);
277 
278 	clen = crp->crp_olen;		/* Length of data after processing */
279 
280 	/* Release the crypto descriptors */
281 	free(tc, M_XDATA), tc = NULL;
282 	crypto_freereq(crp), crp = NULL;
283 
284 	/* In case it's not done already, adjust the size of the mbuf chain */
285 	m->m_pkthdr.len = clen + hlen + skip;
286 
287 	if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
288 		IPCOMPSTAT_INC(ipcomps_hdrops);		/*XXX*/
289 		DPRINTF(("%s: m_pullup failed\n", __func__));
290 		error = EINVAL;				/*XXX*/
291 		goto bad;
292 	}
293 
294 	/* Keep the next protocol field */
295 	addr = (caddr_t) mtod(m, struct ip *) + skip;
296 	nproto = ((struct ipcomp *) addr)->comp_nxt;
297 
298 	/* Remove the IPCOMP header */
299 	error = m_striphdr(m, skip, hlen);
300 	if (error) {
301 		IPCOMPSTAT_INC(ipcomps_hdrops);
302 		DPRINTF(("%s: bad mbuf chain, IPCA %s/%08lx\n", __func__,
303 			 ipsec_address(&sav->sah->saidx.dst),
304 			 (u_long) ntohl(sav->spi)));
305 		goto bad;
306 	}
307 
308 	/* Restore the Next Protocol field */
309 	m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto);
310 
311 	switch (saidx->dst.sa.sa_family) {
312 #ifdef INET6
313 	case AF_INET6:
314 		error = ipsec6_common_input_cb(m, sav, skip, protoff, NULL);
315 		break;
316 #endif
317 #ifdef INET
318 	case AF_INET:
319 		error = ipsec4_common_input_cb(m, sav, skip, protoff, NULL);
320 		break;
321 #endif
322 	default:
323 		panic("%s: Unexpected address family: %d saidx=%p", __func__,
324 		    saidx->dst.sa.sa_family, saidx);
325 	}
326 
327 	KEY_FREESAV(&sav);
328 	return error;
329 bad:
330 	if (sav)
331 		KEY_FREESAV(&sav);
332 	if (m)
333 		m_freem(m);
334 	if (tc != NULL)
335 		free(tc, M_XDATA);
336 	if (crp)
337 		crypto_freereq(crp);
338 	return error;
339 }
340 
341 /*
342  * IPComp output routine, called by ipsec[46]_process_packet()
343  */
344 static int
345 ipcomp_output(
346 	struct mbuf *m,
347 	struct ipsecrequest *isr,
348 	struct mbuf **mp,
349 	int skip,
350 	int protoff
351 )
352 {
353 	struct secasvar *sav;
354 	struct comp_algo *ipcompx;
355 	int error, ralen, maxpacketsize;
356 	struct cryptodesc *crdc;
357 	struct cryptop *crp;
358 	struct tdb_crypto *tc;
359 
360 	sav = isr->sav;
361 	IPSEC_ASSERT(sav != NULL, ("null SA"));
362 	ipcompx = sav->tdb_compalgxform;
363 	IPSEC_ASSERT(ipcompx != NULL, ("null compression xform"));
364 
365 	/*
366 	 * Do not touch the packet in case our payload to compress
367 	 * is lower than the minimal threshold of the compression
368 	 * alogrithm.  We will just send out the data uncompressed.
369 	 * See RFC 3173, 2.2. Non-Expansion Policy.
370 	 */
371 	if (m->m_pkthdr.len <= ipcompx->minlen) {
372 		IPCOMPSTAT_INC(ipcomps_threshold);
373 		return ipsec_process_done(m, isr);
374 	}
375 
376 	ralen = m->m_pkthdr.len - skip;	/* Raw payload length before comp. */
377 	IPCOMPSTAT_INC(ipcomps_output);
378 
379 	/* Check for maximum packet size violations. */
380 	switch (sav->sah->saidx.dst.sa.sa_family) {
381 #ifdef INET
382 	case AF_INET:
383 		maxpacketsize = IP_MAXPACKET;
384 		break;
385 #endif /* INET */
386 #ifdef INET6
387 	case AF_INET6:
388 		maxpacketsize = IPV6_MAXPACKET;
389 		break;
390 #endif /* INET6 */
391 	default:
392 		IPCOMPSTAT_INC(ipcomps_nopf);
393 		DPRINTF(("%s: unknown/unsupported protocol family %d, "
394 		    "IPCA %s/%08lx\n", __func__,
395 		    sav->sah->saidx.dst.sa.sa_family,
396 		    ipsec_address(&sav->sah->saidx.dst),
397 		    (u_long) ntohl(sav->spi)));
398 		error = EPFNOSUPPORT;
399 		goto bad;
400 	}
401 	if (ralen + skip + IPCOMP_HLENGTH > maxpacketsize) {
402 		IPCOMPSTAT_INC(ipcomps_toobig);
403 		DPRINTF(("%s: packet in IPCA %s/%08lx got too big "
404 		    "(len %u, max len %u)\n", __func__,
405 		    ipsec_address(&sav->sah->saidx.dst),
406 		    (u_long) ntohl(sav->spi),
407 		    ralen + skip + IPCOMP_HLENGTH, maxpacketsize));
408 		error = EMSGSIZE;
409 		goto bad;
410 	}
411 
412 	/* Update the counters */
413 	IPCOMPSTAT_ADD(ipcomps_obytes, m->m_pkthdr.len - skip);
414 
415 	m = m_unshare(m, M_NOWAIT);
416 	if (m == NULL) {
417 		IPCOMPSTAT_INC(ipcomps_hdrops);
418 		DPRINTF(("%s: cannot clone mbuf chain, IPCA %s/%08lx\n",
419 		    __func__, ipsec_address(&sav->sah->saidx.dst),
420 		    (u_long) ntohl(sav->spi)));
421 		error = ENOBUFS;
422 		goto bad;
423 	}
424 
425 	/* Ok now, we can pass to the crypto processing. */
426 
427 	/* Get crypto descriptors */
428 	crp = crypto_getreq(1);
429 	if (crp == NULL) {
430 		IPCOMPSTAT_INC(ipcomps_crypto);
431 		DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
432 		error = ENOBUFS;
433 		goto bad;
434 	}
435 	crdc = crp->crp_desc;
436 
437 	/* Compression descriptor */
438 	crdc->crd_skip = skip;
439 	crdc->crd_len = ralen;
440 	crdc->crd_flags = CRD_F_COMP;
441 	crdc->crd_inject = skip;
442 
443 	/* Compression operation */
444 	crdc->crd_alg = ipcompx->type;
445 
446 	/* IPsec-specific opaque crypto info */
447 	tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
448 		M_XDATA, M_NOWAIT|M_ZERO);
449 	if (tc == NULL) {
450 		IPCOMPSTAT_INC(ipcomps_crypto);
451 		DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
452 		crypto_freereq(crp);
453 		error = ENOBUFS;
454 		goto bad;
455 	}
456 
457 	tc->tc_isr = isr;
458 	KEY_ADDREFSA(sav);
459 	tc->tc_sav = sav;
460 	tc->tc_spi = sav->spi;
461 	tc->tc_dst = sav->sah->saidx.dst;
462 	tc->tc_proto = sav->sah->saidx.proto;
463 	tc->tc_protoff = protoff;
464 	tc->tc_skip = skip;
465 
466 	/* Crypto operation descriptor */
467 	crp->crp_ilen = m->m_pkthdr.len;	/* Total input length */
468 	crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
469 	crp->crp_buf = (caddr_t) m;
470 	crp->crp_callback = ipcomp_output_cb;
471 	crp->crp_opaque = (caddr_t) tc;
472 	crp->crp_sid = sav->tdb_cryptoid;
473 
474 	return crypto_dispatch(crp);
475 bad:
476 	if (m)
477 		m_freem(m);
478 	return (error);
479 }
480 
481 /*
482  * IPComp output callback from the crypto driver.
483  */
484 static int
485 ipcomp_output_cb(struct cryptop *crp)
486 {
487 	struct tdb_crypto *tc;
488 	struct ipsecrequest *isr;
489 	struct secasvar *sav;
490 	struct mbuf *m;
491 	int error, skip;
492 
493 	tc = (struct tdb_crypto *) crp->crp_opaque;
494 	IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
495 	m = (struct mbuf *) crp->crp_buf;
496 	skip = tc->tc_skip;
497 
498 	isr = tc->tc_isr;
499 	IPSECREQUEST_LOCK(isr);
500 	sav = tc->tc_sav;
501 	/* With the isr lock released SA pointer can be updated. */
502 	if (sav != isr->sav) {
503 		IPCOMPSTAT_INC(ipcomps_notdb);
504 		DPRINTF(("%s: SA expired while in crypto\n", __func__));
505 		error = ENOBUFS;		/*XXX*/
506 		goto bad;
507 	}
508 
509 	/* Check for crypto errors */
510 	if (crp->crp_etype) {
511 		/* Reset the session ID */
512 		if (sav->tdb_cryptoid != 0)
513 			sav->tdb_cryptoid = crp->crp_sid;
514 
515 		if (crp->crp_etype == EAGAIN) {
516 			IPSECREQUEST_UNLOCK(isr);
517 			return crypto_dispatch(crp);
518 		}
519 		IPCOMPSTAT_INC(ipcomps_noxform);
520 		DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
521 		error = crp->crp_etype;
522 		goto bad;
523 	}
524 	/* Shouldn't happen... */
525 	if (m == NULL) {
526 		IPCOMPSTAT_INC(ipcomps_crypto);
527 		DPRINTF(("%s: bogus return buffer from crypto\n", __func__));
528 		error = EINVAL;
529 		goto bad;
530 	}
531 	IPCOMPSTAT_INC(ipcomps_hist[sav->alg_comp]);
532 
533 	if (crp->crp_ilen - skip > crp->crp_olen) {
534 		struct mbuf *mo;
535 		struct ipcomp *ipcomp;
536 		int roff;
537 		uint8_t prot;
538 
539 		/* Compression helped, inject IPCOMP header. */
540 		mo = m_makespace(m, skip, IPCOMP_HLENGTH, &roff);
541 		if (mo == NULL) {
542 			IPCOMPSTAT_INC(ipcomps_wrap);
543 			DPRINTF(("%s: IPCOMP header inject failed for IPCA %s/%08lx\n",
544 			    __func__, ipsec_address(&sav->sah->saidx.dst),
545 			    (u_long) ntohl(sav->spi)));
546 			error = ENOBUFS;
547 			goto bad;
548 		}
549 		ipcomp = (struct ipcomp *)(mtod(mo, caddr_t) + roff);
550 
551 		/* Initialize the IPCOMP header */
552 		/* XXX alignment always correct? */
553 		switch (sav->sah->saidx.dst.sa.sa_family) {
554 #ifdef INET
555 		case AF_INET:
556 			ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p;
557 			break;
558 #endif /* INET */
559 #ifdef INET6
560 		case AF_INET6:
561 			ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt;
562 			break;
563 #endif
564 		}
565 		ipcomp->comp_flags = 0;
566 		ipcomp->comp_cpi = htons((u_int16_t) ntohl(sav->spi));
567 
568 		/* Fix Next Protocol in IPv4/IPv6 header */
569 		prot = IPPROTO_IPCOMP;
570 		m_copyback(m, tc->tc_protoff, sizeof(u_int8_t),
571 		    (u_char *)&prot);
572 
573 		/* Adjust the length in the IP header */
574 		switch (sav->sah->saidx.dst.sa.sa_family) {
575 #ifdef INET
576 		case AF_INET:
577 			mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
578 			break;
579 #endif /* INET */
580 #ifdef INET6
581 		case AF_INET6:
582 			mtod(m, struct ip6_hdr *)->ip6_plen =
583 				htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr);
584 			break;
585 #endif /* INET6 */
586 		default:
587 			IPCOMPSTAT_INC(ipcomps_nopf);
588 			DPRINTF(("%s: unknown/unsupported protocol "
589 			    "family %d, IPCA %s/%08lx\n", __func__,
590 			    sav->sah->saidx.dst.sa.sa_family,
591 			    ipsec_address(&sav->sah->saidx.dst),
592 			    (u_long) ntohl(sav->spi)));
593 			error = EPFNOSUPPORT;
594 			goto bad;
595 		}
596 	} else {
597 		/* Compression was useless, we have lost time. */
598 		IPCOMPSTAT_INC(ipcomps_uncompr);
599 		DPRINTF(("%s: compressions was useless %d - %d <= %d\n",
600 		    __func__, crp->crp_ilen, skip, crp->crp_olen));
601 		/* XXX remember state to not compress the next couple
602 		 *     of packets, RFC 3173, 2.2. Non-Expansion Policy */
603 	}
604 
605 	/* Release the crypto descriptor */
606 	free(tc, M_XDATA);
607 	crypto_freereq(crp);
608 
609 	/* NB: m is reclaimed by ipsec_process_done. */
610 	error = ipsec_process_done(m, isr);
611 	KEY_FREESAV(&sav);
612 	IPSECREQUEST_UNLOCK(isr);
613 	return error;
614 bad:
615 	if (sav)
616 		KEY_FREESAV(&sav);
617 	IPSECREQUEST_UNLOCK(isr);
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);
639