xref: /netbsd-src/sys/netipsec/xform_ipcomp.c (revision 88fcb00c0357f2d7c1774f86a352637bfda96184)
1 /*	$NetBSD: xform_ipcomp.c,v 1.28 2011/05/06 21:48:46 drochner 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 1.28 2011/05/06 21:48:46 drochner 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 #include <sys/socketvar.h> /* for softnet_lock */
49 
50 #include <netinet/in.h>
51 #include <netinet/in_systm.h>
52 #include <netinet/ip.h>
53 #include <netinet/ip_var.h>
54 
55 #include <net/route.h>
56 #include <netipsec/ipsec.h>
57 #include <netipsec/ipsec_private.h>
58 #include <netipsec/xform.h>
59 
60 #ifdef INET6
61 #include <netinet/ip6.h>
62 #include <netipsec/ipsec6.h>
63 #endif
64 
65 #include <netipsec/ipcomp.h>
66 #include <netipsec/ipcomp_var.h>
67 
68 #include <netipsec/key.h>
69 #include <netipsec/key_debug.h>
70 
71 #include <netipsec/ipsec_osdep.h>
72 
73 #include <opencrypto/cryptodev.h>
74 #include <opencrypto/deflate.h>
75 #include <opencrypto/xform.h>
76 
77 percpu_t *ipcompstat_percpu;
78 
79 int	ipcomp_enable = 1;
80 
81 #ifdef __FreeBSD__
82 SYSCTL_DECL(_net_inet_ipcomp);
83 SYSCTL_INT(_net_inet_ipcomp, OID_AUTO,
84 	ipcomp_enable,	CTLFLAG_RW,	&ipcomp_enable,	0, "");
85 SYSCTL_STRUCT(_net_inet_ipcomp, IPSECCTL_STATS,
86 	stats,		CTLFLAG_RD,	&ipcompstat,	ipcompstat, "");
87 #endif /* __FreeBSD__ */
88 
89 static int ipcomp_input_cb(struct cryptop *crp);
90 static int ipcomp_output_cb(struct cryptop *crp);
91 
92 const struct comp_algo *
93 ipcomp_algorithm_lookup(int alg)
94 {
95 	if (alg >= IPCOMP_ALG_MAX)
96 		return NULL;
97 	switch (alg) {
98 	case SADB_X_CALG_DEFLATE:
99 		return &comp_algo_deflate_nogrow;
100 	}
101 	return NULL;
102 }
103 
104 /*
105  * ipcomp_init() is called when an CPI is being set up.
106  */
107 static int
108 ipcomp_init(struct secasvar *sav, const struct xformsw *xsp)
109 {
110 	const struct comp_algo *tcomp;
111 	struct cryptoini cric;
112 	int ses;
113 
114 	/* NB: algorithm really comes in alg_enc and not alg_comp! */
115 	tcomp = ipcomp_algorithm_lookup(sav->alg_enc);
116 	if (tcomp == NULL) {
117 		DPRINTF(("ipcomp_init: unsupported compression algorithm %d\n",
118 			 sav->alg_comp));
119 		return EINVAL;
120 	}
121 	sav->alg_comp = sav->alg_enc;		/* set for doing histogram */
122 	sav->tdb_xform = xsp;
123 	sav->tdb_compalgxform = tcomp;
124 
125 	/* Initialize crypto session */
126 	memset(&cric, 0, sizeof (cric));
127 	cric.cri_alg = sav->tdb_compalgxform->type;
128 
129 	ses = crypto_newsession(&sav->tdb_cryptoid, &cric, crypto_support);
130 	return ses;
131 }
132 
133 /*
134  * ipcomp_zeroize() used when IPCA is deleted
135  */
136 static int
137 ipcomp_zeroize(struct secasvar *sav)
138 {
139 	int err;
140 
141 	err = crypto_freesession(sav->tdb_cryptoid);
142 	sav->tdb_cryptoid = 0;
143 	return err;
144 }
145 
146 /*
147  * ipcomp_input() gets called to uncompress an input packet
148  */
149 static int
150 ipcomp_input(struct mbuf *m, const struct secasvar *sav, int skip, int protoff)
151 {
152 	struct tdb_crypto *tc;
153 	struct cryptodesc *crdc;
154 	struct cryptop *crp;
155 	int hlen = IPCOMP_HLENGTH;
156 
157 	IPSEC_SPLASSERT_SOFTNET("ipcomp_input");
158 
159 	/* Get crypto descriptors */
160 	crp = crypto_getreq(1);
161 	if (crp == NULL) {
162 		m_freem(m);
163 		DPRINTF(("ipcomp_input: no crypto descriptors\n"));
164 		IPCOMP_STATINC(IPCOMP_STAT_CRYPTO);
165 		return ENOBUFS;
166 	}
167 	/* Get IPsec-specific opaque pointer */
168 	tc = (struct tdb_crypto *) malloc(sizeof (*tc), M_XDATA, M_NOWAIT|M_ZERO);
169 	if (tc == NULL) {
170 		m_freem(m);
171 		crypto_freereq(crp);
172 		DPRINTF(("ipcomp_input: cannot allocate tdb_crypto\n"));
173 		IPCOMP_STATINC(IPCOMP_STAT_CRYPTO);
174 		return ENOBUFS;
175 	}
176 	crdc = crp->crp_desc;
177 
178 	crdc->crd_skip = skip + hlen;
179 	crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
180 	crdc->crd_inject = skip;
181 
182 	tc->tc_ptr = 0;
183 
184 	/* Decompression operation */
185 	crdc->crd_alg = sav->tdb_compalgxform->type;
186 
187 	/* Crypto operation descriptor */
188 	crp->crp_ilen = m->m_pkthdr.len - (skip + hlen);
189 	crp->crp_olen = MCLBYTES; /* hint to decompression code */
190 	crp->crp_flags = CRYPTO_F_IMBUF;
191 	crp->crp_buf = m;
192 	crp->crp_callback = ipcomp_input_cb;
193 	crp->crp_sid = sav->tdb_cryptoid;
194 	crp->crp_opaque = tc;
195 
196 	/* These are passed as-is to the callback */
197 	tc->tc_spi = sav->spi;
198 	tc->tc_dst = sav->sah->saidx.dst;
199 	tc->tc_proto = sav->sah->saidx.proto;
200 	tc->tc_protoff = protoff;
201 	tc->tc_skip = skip;
202 
203 	return crypto_dispatch(crp);
204 }
205 
206 #ifdef INET6
207 #define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {		     \
208 	if (saidx->dst.sa.sa_family == AF_INET6) {			     \
209 		error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
210 	} else {							     \
211 		error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
212 	}								     \
213 } while (0)
214 #else
215 #define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)		     \
216 	(error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
217 #endif
218 
219 /*
220  * IPComp input callback from the crypto driver.
221  */
222 static int
223 ipcomp_input_cb(struct cryptop *crp)
224 {
225 	struct cryptodesc *crd;
226 	struct tdb_crypto *tc;
227 	int skip, protoff;
228 	struct mtag *mtag;
229 	struct mbuf *m;
230 	struct secasvar *sav;
231 	struct secasindex *saidx;
232 	int s, hlen = IPCOMP_HLENGTH, error, clen;
233 	u_int8_t nproto;
234 	void *addr;
235 	u_int16_t dport = 0;
236 	u_int16_t sport = 0;
237 #ifdef IPSEC_NAT_T
238 	struct m_tag * tag = NULL;
239 #endif
240 
241 	crd = crp->crp_desc;
242 
243 	tc = (struct tdb_crypto *) crp->crp_opaque;
244 	IPSEC_ASSERT(tc != NULL, ("ipcomp_input_cb: null opaque crypto data area!"));
245 	skip = tc->tc_skip;
246 	protoff = tc->tc_protoff;
247 	mtag = (struct mtag *) tc->tc_ptr;
248 	m = (struct mbuf *) crp->crp_buf;
249 
250 #ifdef IPSEC_NAT_T
251 	/* find the source port for NAT-T */
252 	if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) {
253 		sport = ((u_int16_t *)(tag + 1))[0];
254 		dport = ((u_int16_t *)(tag + 1))[1];
255 	}
256 #endif
257 
258 	s = splsoftnet();
259 	mutex_enter(softnet_lock);
260 
261 	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport);
262 	if (sav == NULL) {
263 		IPCOMP_STATINC(IPCOMP_STAT_NOTDB);
264 		DPRINTF(("ipcomp_input_cb: SA expired while in crypto\n"));
265 		error = ENOBUFS;		/*XXX*/
266 		goto bad;
267 	}
268 
269 	saidx = &sav->sah->saidx;
270 	IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
271 		saidx->dst.sa.sa_family == AF_INET6,
272 		("ipcomp_input_cb: unexpected protocol family %u",
273 		 saidx->dst.sa.sa_family));
274 
275 	/* Check for crypto errors */
276 	if (crp->crp_etype) {
277 		/* Reset the session ID */
278 		if (sav->tdb_cryptoid != 0)
279 			sav->tdb_cryptoid = crp->crp_sid;
280 
281 		if (crp->crp_etype == EAGAIN) {
282 			KEY_FREESAV(&sav);
283 			mutex_exit(softnet_lock);
284 			splx(s);
285 			return crypto_dispatch(crp);
286 		}
287 
288 		IPCOMP_STATINC(IPCOMP_STAT_NOXFORM);
289 		DPRINTF(("ipcomp_input_cb: crypto error %d\n", crp->crp_etype));
290 		error = crp->crp_etype;
291 		goto bad;
292 	}
293 	/* Shouldn't happen... */
294 	if (m == NULL) {
295 		IPCOMP_STATINC(IPCOMP_STAT_CRYPTO);
296 		DPRINTF(("ipcomp_input_cb: null mbuf returned from crypto\n"));
297 		error = EINVAL;
298 		goto bad;
299 	}
300 	IPCOMP_STATINC(IPCOMP_STAT_HIST + sav->alg_comp);
301 
302 	/* Update the counters */
303 	IPCOMP_STATADD(IPCOMP_STAT_IBYTES, m->m_pkthdr.len - skip - hlen);
304 
305 
306 	clen = crp->crp_olen;		/* Length of data after processing */
307 
308 	/* Release the crypto descriptors */
309 	free(tc, M_XDATA), tc = NULL;
310 	crypto_freereq(crp), crp = NULL;
311 
312 	/* In case it's not done already, adjust the size of the mbuf chain */
313 	m->m_pkthdr.len = clen + hlen + skip;
314 
315 	if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
316 		IPCOMP_STATINC(IPCOMP_STAT_HDROPS);	/*XXX*/
317 		DPRINTF(("ipcomp_input_cb: m_pullup failed\n"));
318 		error = EINVAL;				/*XXX*/
319 		goto bad;
320 	}
321 
322 	/* Keep the next protocol field */
323 	addr = (uint8_t*) mtod(m, struct ip *) + skip;
324 	nproto = ((struct ipcomp *) addr)->comp_nxt;
325 	if (nproto == IPPROTO_IPCOMP || nproto == IPPROTO_AH || nproto == IPPROTO_ESP) {
326 		IPCOMP_STATINC(IPCOMP_STAT_HDROPS);
327 		DPRINTF(("ipcomp_input_cb: nested ipcomp, IPCA %s/%08lx\n",
328 			 ipsec_address(&sav->sah->saidx.dst),
329 			 (u_long) ntohl(sav->spi)));
330 		error = EINVAL;
331 		goto bad;
332 	}
333 
334 	/* Remove the IPCOMP header */
335 	error = m_striphdr(m, skip, hlen);
336 	if (error) {
337 		IPCOMP_STATINC(IPCOMP_STAT_HDROPS);
338 		DPRINTF(("ipcomp_input_cb: bad mbuf chain, IPCA %s/%08lx\n",
339 			 ipsec_address(&sav->sah->saidx.dst),
340 			 (u_long) ntohl(sav->spi)));
341 		goto bad;
342 	}
343 
344 	/* Restore the Next Protocol field */
345 	m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto);
346 
347 	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, NULL);
348 
349 	KEY_FREESAV(&sav);
350 	mutex_exit(softnet_lock);
351 	splx(s);
352 	return error;
353 bad:
354 	if (sav)
355 		KEY_FREESAV(&sav);
356 	mutex_exit(softnet_lock);
357 	splx(s);
358 	if (m)
359 		m_freem(m);
360 	if (tc != NULL)
361 		free(tc, M_XDATA);
362 	if (crp)
363 		crypto_freereq(crp);
364 	return error;
365 }
366 
367 /*
368  * IPComp output routine, called by ipsec[46]_process_packet()
369  */
370 static int
371 ipcomp_output(
372     struct mbuf *m,
373     struct ipsecrequest *isr,
374     struct mbuf **mp,
375     int skip,
376     int protoff
377 )
378 {
379 	const struct secasvar *sav;
380 	const struct comp_algo *ipcompx;
381 	int error, ralen, hlen, maxpacketsize;
382 	struct cryptodesc *crdc;
383 	struct cryptop *crp;
384 	struct tdb_crypto *tc;
385 
386 	IPSEC_SPLASSERT_SOFTNET("ipcomp_output");
387 	sav = isr->sav;
388 	IPSEC_ASSERT(sav != NULL, ("ipcomp_output: null SA"));
389 	ipcompx = sav->tdb_compalgxform;
390 	IPSEC_ASSERT(ipcompx != NULL, ("ipcomp_output: null compression xform"));
391 
392 	ralen = m->m_pkthdr.len - skip;	/* Raw payload length before comp. */
393 
394     /* Don't process the packet if it is too short */
395 	if (ralen < ipcompx->minlen) {
396 		IPCOMP_STATINC(IPCOMP_STAT_MINLEN);
397 		return ipsec_process_done(m,isr);
398 	}
399 
400 	hlen = IPCOMP_HLENGTH;
401 
402 	IPCOMP_STATINC(IPCOMP_STAT_OUTPUT);
403 
404 	/* Check for maximum packet size violations. */
405 	switch (sav->sah->saidx.dst.sa.sa_family) {
406 #ifdef INET
407 	case AF_INET:
408 		maxpacketsize =  IP_MAXPACKET;
409 		break;
410 #endif /* INET */
411 #ifdef INET6
412 	case AF_INET6:
413 		maxpacketsize =  IPV6_MAXPACKET;
414 		break;
415 #endif /* INET6 */
416 	default:
417 		IPCOMP_STATINC(IPCOMP_STAT_NOPF);
418 		DPRINTF(("ipcomp_output: unknown/unsupported protocol family %d"
419 		    ", IPCA %s/%08lx\n",
420 		    sav->sah->saidx.dst.sa.sa_family,
421 		    ipsec_address(&sav->sah->saidx.dst),
422 		    (u_long) ntohl(sav->spi)));
423 		error = EPFNOSUPPORT;
424 		goto bad;
425 	}
426 	if (skip + hlen + ralen > maxpacketsize) {
427 		IPCOMP_STATINC(IPCOMP_STAT_TOOBIG);
428 		DPRINTF(("ipcomp_output: packet in IPCA %s/%08lx got too big "
429 		    "(len %u, max len %u)\n",
430 		    ipsec_address(&sav->sah->saidx.dst),
431 		    (u_long) ntohl(sav->spi),
432 		    skip + hlen + ralen, maxpacketsize));
433 		error = EMSGSIZE;
434 		goto bad;
435 	}
436 
437 	/* Update the counters */
438 	IPCOMP_STATADD(IPCOMP_STAT_OBYTES, m->m_pkthdr.len - skip);
439 
440 	m = m_clone(m);
441 	if (m == NULL) {
442 		IPCOMP_STATINC(IPCOMP_STAT_HDROPS);
443 		DPRINTF(("ipcomp_output: cannot clone mbuf chain, IPCA %s/%08lx\n",
444 		    ipsec_address(&sav->sah->saidx.dst),
445 		    (u_long) ntohl(sav->spi)));
446 		error = ENOBUFS;
447 		goto bad;
448 	}
449 
450 	/* Ok now, we can pass to the crypto processing */
451 
452 	/* Get crypto descriptors */
453 	crp = crypto_getreq(1);
454 	if (crp == NULL) {
455 		IPCOMP_STATINC(IPCOMP_STAT_CRYPTO);
456 		DPRINTF(("ipcomp_output: failed to acquire crypto descriptor\n"));
457 		error = ENOBUFS;
458 		goto bad;
459 	}
460 	crdc = crp->crp_desc;
461 
462 	/* Compression descriptor */
463 	crdc->crd_skip = skip;
464 	crdc->crd_len = m->m_pkthdr.len - skip;
465 	crdc->crd_flags = CRD_F_COMP;
466 	crdc->crd_inject = skip;
467 
468 	/* Compression operation */
469 	crdc->crd_alg = ipcompx->type;
470 
471 	/* IPsec-specific opaque crypto info */
472 	tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
473 		M_XDATA, M_NOWAIT|M_ZERO);
474 	if (tc == NULL) {
475 		IPCOMP_STATINC(IPCOMP_STAT_CRYPTO);
476 		DPRINTF(("ipcomp_output: failed to allocate tdb_crypto\n"));
477 		crypto_freereq(crp);
478 		error = ENOBUFS;
479 		goto bad;
480 	}
481 
482 	tc->tc_isr = isr;
483 	tc->tc_spi = sav->spi;
484 	tc->tc_dst = sav->sah->saidx.dst;
485 	tc->tc_proto = sav->sah->saidx.proto;
486 	tc->tc_skip = skip;
487 	tc->tc_protoff = protoff;
488 
489 	/* Crypto operation descriptor */
490 	crp->crp_ilen = m->m_pkthdr.len;	/* Total input length */
491 	crp->crp_flags = CRYPTO_F_IMBUF;
492 	crp->crp_buf = m;
493 	crp->crp_callback = ipcomp_output_cb;
494 	crp->crp_opaque = tc;
495 	crp->crp_sid = sav->tdb_cryptoid;
496 
497 	return crypto_dispatch(crp);
498 bad:
499 	if (m)
500 		m_freem(m);
501 	return (error);
502 }
503 
504 /*
505  * IPComp output callback from the crypto driver.
506  */
507 static int
508 ipcomp_output_cb(struct cryptop *crp)
509 {
510 	struct tdb_crypto *tc;
511 	struct ipsecrequest *isr;
512 	struct secasvar *sav;
513 	struct mbuf *m, *mo;
514 	int s, error, skip, rlen, roff;
515 	u_int8_t prot;
516 	u_int16_t cpi;
517 	struct ipcomp * ipcomp;
518 
519 
520 	tc = (struct tdb_crypto *) crp->crp_opaque;
521 	IPSEC_ASSERT(tc != NULL, ("ipcomp_output_cb: null opaque data area!"));
522 	m = (struct mbuf *) crp->crp_buf;
523 	skip = tc->tc_skip;
524 	rlen = crp->crp_ilen - skip;
525 
526 	s = splsoftnet();
527 	mutex_enter(softnet_lock);
528 
529 	isr = tc->tc_isr;
530 	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0);
531 	if (sav == NULL) {
532 		IPCOMP_STATINC(IPCOMP_STAT_NOTDB);
533 		DPRINTF(("ipcomp_output_cb: SA expired while in crypto\n"));
534 		error = ENOBUFS;		/*XXX*/
535 		goto bad;
536 	}
537 	IPSEC_ASSERT(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 			mutex_exit(softnet_lock);
548 			splx(s);
549 			return crypto_dispatch(crp);
550 		}
551 		IPCOMP_STATINC(IPCOMP_STAT_NOXFORM);
552 		DPRINTF(("ipcomp_output_cb: crypto error %d\n", crp->crp_etype));
553 		error = crp->crp_etype;
554 		goto bad;
555 	}
556 	/* Shouldn't happen... */
557 	if (m == NULL) {
558 		IPCOMP_STATINC(IPCOMP_STAT_CRYPTO);
559 		DPRINTF(("ipcomp_output_cb: bogus return buffer from crypto\n"));
560 		error = EINVAL;
561 		goto bad;
562 	}
563 	IPCOMP_STATINC(IPCOMP_STAT_HIST + sav->alg_comp);
564 
565 	if (rlen > crp->crp_olen) {
566 		/* Inject IPCOMP header */
567 		mo = m_makespace(m, skip, IPCOMP_HLENGTH, &roff);
568 		if (mo == NULL) {
569 			IPCOMP_STATINC(IPCOMP_STAT_WRAP);
570 			DPRINTF(("ipcomp_output: failed to inject IPCOMP header for "
571 					 "IPCA %s/%08lx\n",
572 						ipsec_address(&sav->sah->saidx.dst),
573 						(u_long) ntohl(sav->spi)));
574 			error = ENOBUFS;
575 			goto bad;
576 		}
577 		ipcomp = (struct ipcomp *)(mtod(mo, char *) + roff);
578 
579 		/* Initialize the IPCOMP header */
580 		/* XXX alignment always correct? */
581 		switch (sav->sah->saidx.dst.sa.sa_family) {
582 #ifdef INET
583 		case AF_INET:
584 			ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p;
585 			 break;
586 #endif /* INET */
587 #ifdef INET6
588 		case AF_INET6:
589 			ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt;
590 		break;
591 #endif
592 		}
593 		ipcomp->comp_flags = 0;
594 
595 		if ((sav->flags & SADB_X_EXT_RAWCPI) == 0)
596 			 cpi = sav->alg_enc;
597 		else
598 			cpi = ntohl(sav->spi) & 0xffff;
599 		ipcomp->comp_cpi = htons(cpi);
600 
601 		/* Fix Next Protocol in IPv4/IPv6 header */
602 		prot = IPPROTO_IPCOMP;
603 		m_copyback(m, tc->tc_protoff, sizeof(u_int8_t), (u_char *)&prot);
604 
605 		/* Adjust the length in the IP header */
606 		switch (sav->sah->saidx.dst.sa.sa_family) {
607 #ifdef INET
608 		case AF_INET:
609 			mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
610 			break;
611 #endif /* INET */
612 #ifdef INET6
613 		case AF_INET6:
614 			mtod(m, struct ip6_hdr *)->ip6_plen =
615 				htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr);
616 			break;
617 #endif /* INET6 */
618 		default:
619 			IPCOMP_STATINC(IPCOMP_STAT_NOPF);
620 			DPRINTF(("ipcomp_output: unknown/unsupported protocol "
621 			    "family %d, IPCA %s/%08lx\n",
622 			    sav->sah->saidx.dst.sa.sa_family,
623 			    ipsec_address(&sav->sah->saidx.dst),
624 			    (u_long) ntohl(sav->spi)));
625 			error = EPFNOSUPPORT;
626 			goto bad;
627 		}
628 	} else {
629 		/* compression was useless, we have lost time */
630 		IPCOMP_STATINC(IPCOMP_STAT_USELESS);
631 		DPRINTF(("ipcomp_output_cb: compression was useless : initial size was %d"
632 				   	"and compressed size is %d\n", rlen, crp->crp_olen));
633 	}
634 
635 
636 	/* Release the crypto descriptor */
637 	free(tc, M_XDATA);
638 	crypto_freereq(crp);
639 
640 	/* NB: m is reclaimed by ipsec_process_done. */
641 	error = ipsec_process_done(m, isr);
642 	KEY_FREESAV(&sav);
643 	mutex_exit(softnet_lock);
644 	splx(s);
645 	return error;
646 bad:
647 	if (sav)
648 		KEY_FREESAV(&sav);
649 	mutex_exit(softnet_lock);
650 	splx(s);
651 	if (m)
652 		m_freem(m);
653 	free(tc, M_XDATA);
654 	crypto_freereq(crp);
655 	return error;
656 }
657 
658 static struct xformsw ipcomp_xformsw = {
659 	XF_IPCOMP,		XFT_COMP,		"IPcomp",
660 	ipcomp_init,		ipcomp_zeroize,		ipcomp_input,
661 	ipcomp_output,
662 	NULL,
663 };
664 
665 INITFN void
666 ipcomp_attach(void)
667 {
668 	ipcompstat_percpu = percpu_alloc(sizeof(uint64_t) * IPCOMP_NSTATS);
669 	xform_register(&ipcomp_xformsw);
670 }
671 
672 #ifdef __FreeBSD__
673 SYSINIT(ipcomp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, ipcomp_attach, NULL)
674 #endif /* __FreeBSD__ */
675