[dragonfly.git] / sys / netproto / ipsec / xform_ipcomp.c

/*	$FreeBSD: src/sys/netipsec/xform_ipcomp.c,v 1.1.4.2 2003/02/26 00:14:06 sam Exp $	*/
/*	$DragonFly: src/sys/netproto/ipsec/xform_ipcomp.c,v 1.10 2006/10/12 01:32:51 hsu Exp $	*/
/* $OpenBSD: ip_ipcomp.c,v 1.1 2001/07/05 12:08:52 jjbg Exp $ */

/*
 * Copyright (c) 2001 Jean-Jacques Bernard-Gundol (jj@wabbitt.org)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* IP payload compression protocol (IPComp), see RFC 2393 */
#include "opt_inet.h"
#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/protosw.h>
#include <sys/sysctl.h>
#include <sys/thread2.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>

#include <net/route.h>
#include <netproto/ipsec/ipsec.h>
#include <netproto/ipsec/xform.h>

#ifdef INET6
#include <netinet/ip6.h>
#include <netproto/ipsec/ipsec6.h>
#endif

#include <netproto/ipsec/ipcomp.h>
#include <netproto/ipsec/ipcomp_var.h>

#include <netproto/ipsec/key.h>
#include <netproto/ipsec/key_debug.h>

#include <opencrypto/cryptodev.h>
#include <opencrypto/deflate.h>
#include <opencrypto/xform.h>

int	ipcomp_enable = 0;
struct	ipcompstat ipcompstat;

SYSCTL_DECL(_net_inet_ipcomp);
SYSCTL_INT(_net_inet_ipcomp, OID_AUTO,
	ipcomp_enable,	CTLFLAG_RW,	&ipcomp_enable,	0, "");
SYSCTL_STRUCT(_net_inet_ipcomp, IPSECCTL_STATS,
	stats,		CTLFLAG_RD,	&ipcompstat,	ipcompstat, "");

static int ipcomp_input_cb(struct cryptop *crp);
static int ipcomp_output_cb(struct cryptop *crp);

struct comp_algo *
ipcomp_algorithm_lookup(int alg)
{
	if (alg >= IPCOMP_ALG_MAX)
		return NULL;
	switch (alg) {
	case SADB_X_CALG_DEFLATE:
		return &comp_algo_deflate;
	}
	return NULL;
}

/*
 * ipcomp_init() is called when an CPI is being set up.
 */
static int
ipcomp_init(struct secasvar *sav, struct xformsw *xsp)
{
	struct comp_algo *tcomp;
	struct cryptoini cric;

	/* NB: algorithm really comes in alg_enc and not alg_comp! */
	tcomp = ipcomp_algorithm_lookup(sav->alg_enc);
	if (tcomp == NULL) {
		DPRINTF(("ipcomp_init: unsupported compression algorithm %d\n",
			 sav->alg_comp));
		return EINVAL;
	}
	sav->alg_comp = sav->alg_enc;		/* set for doing histogram */
	sav->tdb_xform = xsp;
	sav->tdb_compalgxform = tcomp;

	/* Initialize crypto session */
	bzero(&cric, sizeof (cric));
	cric.cri_alg = sav->tdb_compalgxform->type;

	return crypto_newsession(&sav->tdb_cryptoid, &cric, crypto_support);
}

/*
 * ipcomp_zeroize() used when IPCA is deleted
 */
static int
ipcomp_zeroize(struct secasvar *sav)
{
	int err;

	err = crypto_freesession(sav->tdb_cryptoid);
	sav->tdb_cryptoid = 0;
	return err;
}

/*
 * ipcomp_input() gets called to uncompress an input packet
 */
static int
ipcomp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
{
	struct tdb_crypto *tc;
	struct cryptodesc *crdc;
	struct cryptop *crp;
	struct ipcomp *ipcomp;
	caddr_t addr;
	int hlen = IPCOMP_HLENGTH;

	/*
	 * Check that the next header of the IPComp is not IPComp again, before
	 * doing any real work.  Given it is not possible to do double
	 * compression it means someone is playing tricks on us.
	 */
	if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == NULL) {
		ipcompstat.ipcomps_hdrops++;		/*XXX*/
		DPRINTF(("%s: m_pullup failed\n", __func__));
		return (ENOBUFS);
	}
	addr = (caddr_t) mtod(m, struct ip *) + skip;
	ipcomp = (struct ipcomp *)addr;
	if (ipcomp->comp_nxt == IPPROTO_IPCOMP) {
		m_freem(m);
		ipcompstat.ipcomps_pdrops++;	/* XXX have our own stats? */
		DPRINTF(("%s: recursive compression detected\n", __func__));
		return (EINVAL);
	}

	/* Get crypto descriptors */
	crp = crypto_getreq(1);
	if (crp == NULL) {
		m_freem(m);
		DPRINTF(("ipcomp_input: no crypto descriptors\n"));
		ipcompstat.ipcomps_crypto++;
		return ENOBUFS;
	}
	/* Get IPsec-specific opaque pointer */
	tc = kmalloc(sizeof (*tc), M_XDATA, 
		    M_INTWAIT | M_ZERO | M_NULLOK);
	if (tc == NULL) {
		m_freem(m);
		crypto_freereq(crp);
		DPRINTF(("ipcomp_input: cannot allocate tdb_crypto\n"));
		ipcompstat.ipcomps_crypto++;
		return ENOBUFS;
	}
	crdc = crp->crp_desc;

	crdc->crd_skip = skip + hlen;
	crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
	crdc->crd_inject = skip;

	tc->tc_ptr = 0;

	/* Decompression operation */
	crdc->crd_alg = sav->tdb_compalgxform->type;

	/* Crypto operation descriptor */
	crp->crp_ilen = m->m_pkthdr.len - (skip + hlen);
	crp->crp_flags = CRYPTO_F_IMBUF;
	crp->crp_buf = (caddr_t) m;
	crp->crp_callback = ipcomp_input_cb;
	crp->crp_sid = sav->tdb_cryptoid;
	crp->crp_opaque = (caddr_t) tc;

	/* These are passed as-is to the callback */
	tc->tc_spi = sav->spi;
	tc->tc_dst = sav->sah->saidx.dst;
	tc->tc_proto = sav->sah->saidx.proto;
	tc->tc_protoff = protoff;
	tc->tc_skip = skip;

	return crypto_dispatch(crp);
}

#ifdef INET6
#define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {		     \
	if (saidx->dst.sa.sa_family == AF_INET6) {			     \
		error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
	} else {							     \
		error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
	}								     \
} while (0)
#else
#define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)		     \
	(error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
#endif

/*
 * IPComp input callback from the crypto driver.
 */
static int
ipcomp_input_cb(struct cryptop *crp)
{
	struct cryptodesc *crd;
	struct tdb_crypto *tc;
	int skip, protoff;
	struct mtag *mtag;
	struct mbuf *m;
	struct secasvar *sav;
	struct secasindex *saidx;
	int hlen = IPCOMP_HLENGTH, error, clen;
	u_int8_t nproto;
	caddr_t addr;

	crd = crp->crp_desc;

	tc = (struct tdb_crypto *) crp->crp_opaque;
	KASSERT(tc != NULL, ("ipcomp_input_cb: null opaque crypto data area!"));
	skip = tc->tc_skip;
	protoff = tc->tc_protoff;
	mtag = (struct mtag *) tc->tc_ptr;
	m = (struct mbuf *) crp->crp_buf;

	crit_enter();

	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
	if (sav == NULL) {
		ipcompstat.ipcomps_notdb++;
		DPRINTF(("ipcomp_input_cb: SA expired while in crypto\n"));
		error = ENOBUFS;		/*XXX*/
		goto bad;
	}

	saidx = &sav->sah->saidx;
	KASSERT(saidx->dst.sa.sa_family == AF_INET ||
		saidx->dst.sa.sa_family == AF_INET6,
		("ah_input_cb: unexpected protocol family %u",
		 saidx->dst.sa.sa_family));

	/* Check for crypto errors */
	if (crp->crp_etype) {
		/* Reset the session ID */
		if (sav->tdb_cryptoid != 0)
			sav->tdb_cryptoid = crp->crp_sid;

		if (crp->crp_etype == EAGAIN) {
			KEY_FREESAV(&sav);
			crit_exit();
			return crypto_dispatch(crp);
		}

		ipcompstat.ipcomps_noxform++;
		DPRINTF(("ipcomp_input_cb: crypto error %d\n", crp->crp_etype));
		error = crp->crp_etype;
		goto bad;
	}
	/* Shouldn't happen... */
	if (m == NULL) {
		ipcompstat.ipcomps_crypto++;
		DPRINTF(("ipcomp_input_cb: null mbuf returned from crypto\n"));
		error = EINVAL;
		goto bad;
	}
	ipcompstat.ipcomps_hist[sav->alg_comp]++;

	clen = crp->crp_olen;		/* Length of data after processing */

	/* Release the crypto descriptors */
	kfree(tc, M_XDATA), tc = NULL;
	crypto_freereq(crp), crp = NULL;

	/* In case it's not done already, adjust the size of the mbuf chain */
	m->m_pkthdr.len = clen + hlen + skip;

	if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
		ipcompstat.ipcomps_hdrops++;		/*XXX*/
		DPRINTF(("ipcomp_input_cb: m_pullup failed\n"));
		error = EINVAL;				/*XXX*/
		goto bad;
	}

	/* Keep the next protocol field */
	addr = (caddr_t) mtod(m, struct ip *) + skip;
	nproto = ((struct ipcomp *) addr)->comp_nxt;

	/* Remove the IPCOMP header */
	error = m_striphdr(m, skip, hlen);
	if (error) {
		ipcompstat.ipcomps_hdrops++;
		DPRINTF(("ipcomp_input_cb: bad mbuf chain, IPCA %s/%08lx\n",
			 ipsec_address(&sav->sah->saidx.dst),
			 (u_long) ntohl(sav->spi)));
		goto bad;
	}

	/* Restore the Next Protocol field */
	m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto);

	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, NULL);

	KEY_FREESAV(&sav);
	crit_exit();
	return error;
bad:
	if (sav)
		KEY_FREESAV(&sav);
	crit_exit();
	if (m)
		m_freem(m);
	if (tc != NULL)
		kfree(tc, M_XDATA);
	if (crp)
		crypto_freereq(crp);
	return error;
}

/*
 * IPComp output routine, called by ipsec[46]_process_packet()
 */
static int
ipcomp_output(
	struct mbuf *m,
	struct ipsecrequest *isr,
	struct mbuf **mp,
	int skip,
	int protoff
)
{
	struct secasvar *sav;
	struct comp_algo *ipcompx;
	int error, ralen, hlen, maxpacketsize, roff;
	u_int8_t prot;
	struct cryptodesc *crdc;
	struct cryptop *crp;
	struct tdb_crypto *tc;
	struct mbuf *mo;
	struct ipcomp *ipcomp;

	sav = isr->sav;
	KASSERT(sav != NULL, ("ipcomp_output: null SA"));
	ipcompx = sav->tdb_compalgxform;
	KASSERT(ipcompx != NULL, ("ipcomp_output: null compression xform"));

	ralen = m->m_pkthdr.len - skip;	/* Raw payload length before comp. */
	hlen = IPCOMP_HLENGTH;

	ipcompstat.ipcomps_output++;

	/* Check for maximum packet size violations. */
	switch (sav->sah->saidx.dst.sa.sa_family) {
#ifdef INET
	case AF_INET:
		maxpacketsize =  IP_MAXPACKET;
		break;
#endif /* INET */
#ifdef INET6
	case AF_INET6:
		maxpacketsize =  IPV6_MAXPACKET;
		break;
#endif /* INET6 */
	default:
		ipcompstat.ipcomps_nopf++;
		DPRINTF(("ipcomp_output: unknown/unsupported protocol family %d"
		    ", IPCA %s/%08lx\n", 
		    sav->sah->saidx.dst.sa.sa_family,
		    ipsec_address(&sav->sah->saidx.dst),
		    (u_long) ntohl(sav->spi)));
		error = EPFNOSUPPORT;
		goto bad;
	}
	if (skip + hlen + ralen > maxpacketsize) {
		ipcompstat.ipcomps_toobig++;
		DPRINTF(("ipcomp_output: packet in IPCA %s/%08lx got too big "
		    "(len %u, max len %u)\n",
		    ipsec_address(&sav->sah->saidx.dst),
		    (u_long) ntohl(sav->spi),
		    skip + hlen + ralen, maxpacketsize));
		error = EMSGSIZE;
		goto bad;
	}

	/* Update the counters */
	ipcompstat.ipcomps_obytes += m->m_pkthdr.len - skip;

	m = m_clone(m);
	if (m == NULL) {
		ipcompstat.ipcomps_hdrops++;
		DPRINTF(("ipcomp_output: cannot clone mbuf chain, IPCA %s/%08lx\n", 
		    ipsec_address(&sav->sah->saidx.dst),
		    (u_long) ntohl(sav->spi)));
		error = ENOBUFS;
		goto bad;
	}

	/* Inject IPCOMP header */
	mo = m_makespace(m, skip, hlen, &roff);
	if (mo == NULL) {
		ipcompstat.ipcomps_wrap++;
		DPRINTF(("ipcomp_output: failed to inject IPCOMP header for "
		    "IPCA %s/%08lx\n",
		    ipsec_address(&sav->sah->saidx.dst),
		    (u_long) ntohl(sav->spi)));
		error = ENOBUFS;
		goto bad;
	}
	ipcomp = (struct ipcomp *)(mtod(mo, caddr_t) + roff);

	/* Initialize the IPCOMP header */
	/* XXX alignment always correct? */
	switch (sav->sah->saidx.dst.sa.sa_family) {
#ifdef INET
	case AF_INET:
		ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p;
		break;
#endif /* INET */
#ifdef INET6
	case AF_INET6:
		ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt;
		break;
#endif
	}
	ipcomp->comp_flags = 0;
	ipcomp->comp_cpi = htons((u_int16_t) ntohl(sav->spi));

	/* Fix Next Protocol in IPv4/IPv6 header */
	prot = IPPROTO_IPCOMP;
	m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);

	/* Ok now, we can pass to the crypto processing */

	/* Get crypto descriptors */
	crp = crypto_getreq(1);
	if (crp == NULL) {
		ipcompstat.ipcomps_crypto++;
		DPRINTF(("ipcomp_output: failed to acquire crypto descriptor\n"));
		error = ENOBUFS;
		goto bad;
	}
	crdc = crp->crp_desc;

	/* Compression descriptor */
	crdc->crd_skip = skip + hlen;
	crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
	crdc->crd_flags = CRD_F_COMP;
	crdc->crd_inject = skip + hlen;

	/* Compression operation */
	crdc->crd_alg = ipcompx->type;

	/* IPsec-specific opaque crypto info */
	tc = kmalloc(sizeof(struct tdb_crypto),
		    M_XDATA, M_INTWAIT | M_ZERO | M_NULLOK);
	if (tc == NULL) {
		ipcompstat.ipcomps_crypto++;
		DPRINTF(("ipcomp_output: failed to allocate tdb_crypto\n"));
		crypto_freereq(crp);
		error = ENOBUFS;
		goto bad;
	}

	tc->tc_isr = isr;
	tc->tc_spi = sav->spi;
	tc->tc_dst = sav->sah->saidx.dst;
	tc->tc_proto = sav->sah->saidx.proto;
	tc->tc_skip = skip + hlen;

	/* Crypto operation descriptor */
	crp->crp_ilen = m->m_pkthdr.len;	/* Total input length */
	crp->crp_flags = CRYPTO_F_IMBUF;
	crp->crp_buf = (caddr_t) m;
	crp->crp_callback = ipcomp_output_cb;
	crp->crp_opaque = (caddr_t) tc;
	crp->crp_sid = sav->tdb_cryptoid;

	return crypto_dispatch(crp);
bad:
	if (m)
		m_freem(m);
	return (error);
}

/*
 * IPComp output callback from the crypto driver.
 */
static int
ipcomp_output_cb(struct cryptop *crp)
{
	struct tdb_crypto *tc;
	struct ipsecrequest *isr;
	struct secasvar *sav;
	struct mbuf *m;
	int error, skip, rlen;

	tc = (struct tdb_crypto *) crp->crp_opaque;
	KASSERT(tc != NULL, ("ipcomp_output_cb: null opaque data area!"));
	m = (struct mbuf *) crp->crp_buf;
	skip = tc->tc_skip;
	rlen = crp->crp_ilen - skip;

	crit_enter();

	isr = tc->tc_isr;
	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
	if (sav == NULL) {
		ipcompstat.ipcomps_notdb++;
		DPRINTF(("ipcomp_output_cb: SA expired while in crypto\n"));
		error = ENOBUFS;		/*XXX*/
		goto bad;
	}
	KASSERT(isr->sav == sav, ("ipcomp_output_cb: SA changed\n"));

	/* Check for crypto errors */
	if (crp->crp_etype) {
		/* Reset session ID */
		if (sav->tdb_cryptoid != 0)
			sav->tdb_cryptoid = crp->crp_sid;

		if (crp->crp_etype == EAGAIN) {
			KEY_FREESAV(&sav);
			crit_exit();
			return crypto_dispatch(crp);
		}
		ipcompstat.ipcomps_noxform++;
		DPRINTF(("ipcomp_output_cb: crypto error %d\n", crp->crp_etype));
		error = crp->crp_etype;
		goto bad;
	}
	/* Shouldn't happen... */
	if (m == NULL) {
		ipcompstat.ipcomps_crypto++;
		DPRINTF(("ipcomp_output_cb: bogus return buffer from crypto\n"));
		error = EINVAL;
		goto bad;
	}
	ipcompstat.ipcomps_hist[sav->alg_comp]++;

	if (rlen > crp->crp_olen) {
		/* Adjust the length in the IP header */
		switch (sav->sah->saidx.dst.sa.sa_family) {
#ifdef INET
		case AF_INET:
			mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
			break;
#endif /* INET */
#ifdef INET6
		case AF_INET6:
			mtod(m, struct ip6_hdr *)->ip6_plen =
				htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr);
			break;
#endif /* INET6 */
		default:
			ipcompstat.ipcomps_nopf++;
			DPRINTF(("ipcomp_output: unknown/unsupported protocol "
			    "family %d, IPCA %s/%08lx\n", 
			    sav->sah->saidx.dst.sa.sa_family,
			    ipsec_address(&sav->sah->saidx.dst), 
			    (u_long) ntohl(sav->spi)));
			error = EPFNOSUPPORT;
			goto bad;
		}
	} else {
		/* compression was useless, we have lost time */
		/* XXX add statistic */
	}

	/* Release the crypto descriptor */
	kfree(tc, M_XDATA);
	crypto_freereq(crp);

	/* NB: m is reclaimed by ipsec_process_done. */
	error = ipsec_process_done(m, isr);
	KEY_FREESAV(&sav);
	crit_exit();
	return error;
bad:
	if (sav)
		KEY_FREESAV(&sav);
	crit_exit();
	if (m)
		m_freem(m);
	kfree(tc, M_XDATA);
	crypto_freereq(crp);
	return error;
}

static struct xformsw ipcomp_xformsw = {
	XF_IPCOMP,		XFT_COMP,		"IPcomp",
	ipcomp_init,		ipcomp_zeroize,		ipcomp_input,
	ipcomp_output
};

static void
ipcomp_attach(void)
{
	xform_register(&ipcomp_xformsw);
}
SYSINIT(ipcomp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, ipcomp_attach, NULL)
Commit	Line	Data
984263bc	1	/* $FreeBSD: src/sys/netipsec/xform_ipcomp.c,v 1.1.4.2 2003/02/26 00:14:06 sam Exp $ */
896d25fc	2	/* $DragonFly: src/sys/netproto/ipsec/xform_ipcomp.c,v 1.10 2006/10/12 01:32:51 hsu Exp $ */
984263bc MD	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>
221b8f43	43	#include <sys/thread2.h>
984263bc MD	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>
bf844ffa JH	51	#include <netproto/ipsec/ipsec.h>
bf844ffa JH	52	#include <netproto/ipsec/xform.h>
984263bc MD	53
	54	#ifdef INET6
	55	#include <netinet/ip6.h>
bf844ffa	56	#include <netproto/ipsec/ipsec6.h>
984263bc MD	57	#endif
984263bc MD	58
bf844ffa JH	59	#include <netproto/ipsec/ipcomp.h>
bf844ffa JH	60	#include <netproto/ipsec/ipcomp_var.h>
984263bc	61
bf844ffa JH	62	#include <netproto/ipsec/key.h>
bf844ffa JH	63	#include <netproto/ipsec/key_debug.h>
984263bc MD	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;
1327d18c MD	142	struct ipcomp *ipcomp;
1327d18c MD	143	caddr_t addr;
984263bc MD	144	int hlen = IPCOMP_HLENGTH;
984263bc MD	145
1327d18c MD	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
984263bc MD	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 */
efda3bd0	174	tc = kmalloc(sizeof (*tc), M_XDATA,
062eab50	175	M_INTWAIT \| M_ZERO \| M_NULLOK);
984263bc MD	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;
cb753a0e	238	int hlen = IPCOMP_HLENGTH, error, clen;
984263bc MD	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
cb753a0e	251	crit_enter();
984263bc MD	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);
cb753a0e	275	crit_exit();
984263bc MD	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 */
efda3bd0	296	kfree(tc, M_XDATA), tc = NULL;
984263bc MD	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);
cb753a0e	329	crit_exit();
984263bc MD	330	return error;
	331	bad:
	332	if (sav)
	333	KEY_FREESAV(&sav);
cb753a0e	334	crit_exit();
984263bc MD	335	if (m)
	336	m_freem(m);
	337	if (tc != NULL)
efda3bd0	338	kfree(tc, M_XDATA);
984263bc MD	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
984263bc MD	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 */
896d25fc	478	tc = kmalloc(sizeof(struct tdb_crypto),
062eab50	479	M_XDATA, M_INTWAIT \| M_ZERO \| M_NULLOK);
984263bc MD	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;
cb753a0e	519	int error, skip, rlen;
984263bc MD	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
cb753a0e	527	crit_enter();
984263bc MD	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);
cb753a0e	547	crit_exit();
984263bc MD	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 */
efda3bd0	594	kfree(tc, M_XDATA);
984263bc MD	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);
cb753a0e	600	crit_exit();
984263bc MD	601	return error;
	602	bad:
	603	if (sav)
	604	KEY_FREESAV(&sav);
cb753a0e	605	crit_exit();
984263bc MD	606	if (m)
984263bc MD	607	m_freem(m);
efda3bd0	608	kfree(tc, M_XDATA);
984263bc MD	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)