[apple/xnu.git] / bsd / netinet6 / ah_output.c

/*	$FreeBSD: src/sys/netinet6/ah_output.c,v 1.1.2.3 2001/07/03 11:01:49 ume Exp $	*/
/*	$KAME: ah_output.c,v 1.30 2001/02/21 00:50:53 itojun Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * 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. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``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 PROJECT OR CONTRIBUTORS 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.
 */

/*
 * RFC1826/2402 authentication header.
 */

#define _IP_VHL

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>

#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_var.h>

#if INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#endif

#include <netinet6/ipsec.h>
#if INET6
#include <netinet6/ipsec6.h>
#endif
#include <netinet6/ah.h>
#if INET6
#include <netinet6/ah6.h>
#endif
#include <netkey/key.h>
#include <netkey/keydb.h>

#include <net/net_osdep.h>

#if INET
static struct in_addr *ah4_finaldst __P((struct mbuf *));
#endif

/*
 * compute AH header size.
 * transport mode only.  for tunnel mode, we should implement
 * virtual interface, and control MTU/MSS by the interface MTU.
 */
size_t
ah_hdrsiz(isr)
	struct ipsecrequest *isr;
{
	const struct ah_algorithm *algo;
	size_t hdrsiz;

	/* sanity check */
	if (isr == NULL)
		panic("ah_hdrsiz: NULL was passed.\n");

	if (isr->saidx.proto != IPPROTO_AH)
		panic("unsupported mode passed to ah_hdrsiz");

	if (isr->sav == NULL)
		goto estimate;
	if (isr->sav->state != SADB_SASTATE_MATURE
	 && isr->sav->state != SADB_SASTATE_DYING)
		goto estimate;

	/* we need transport mode AH. */
	algo = ah_algorithm_lookup(isr->sav->alg_auth);
	if (!algo)
		goto estimate;

	/*
	 * XXX
	 * right now we don't calcurate the padding size.  simply
	 * treat the padding size as constant, for simplicity.
	 *
	 * XXX variable size padding support
	 */
	hdrsiz = (((*algo->sumsiz)(isr->sav) + 3) & ~(4 - 1));
	if (isr->sav->flags & SADB_X_EXT_OLD)
		hdrsiz += sizeof(struct ah);
	else
		hdrsiz += sizeof(struct newah);

	return hdrsiz;

    estimate:
	/* ASSUMING:
	 *	sizeof(struct newah) > sizeof(struct ah).
	 *	16 = (16 + 3) & ~(4 - 1).
	 */
	return sizeof(struct newah) + 16;
}

#if INET
/*
 * Modify the packet so that it includes the authentication data.
 * The mbuf passed must start with IPv4 header.
 *
 * assumes that the first mbuf contains IPv4 header + option only.
 * the function does not modify m.
 */
int
ah4_output(m, isr)
	struct mbuf *m;
	struct ipsecrequest *isr;
{
	struct secasvar *sav = isr->sav;
	const struct ah_algorithm *algo;
	u_int32_t spi;
	u_char *ahdrpos;
	u_char *ahsumpos = NULL;
	size_t hlen = 0;	/*IP header+option in bytes*/
	size_t plen = 0;	/*AH payload size in bytes*/
	size_t ahlen = 0;	/*plen + sizeof(ah)*/
	struct ip *ip;
	struct in_addr dst;
	struct in_addr *finaldst;
	int error;

	/* sanity checks */
	if ((sav->flags & SADB_X_EXT_OLD) == 0 && !sav->replay) {
		struct ip *ip;

		ip = mtod(m, struct ip *);
		ipseclog((LOG_DEBUG, "ah4_output: internal error: "
			"sav->replay is null: %x->%x, SPI=%u\n",
			(u_int32_t)ntohl(ip->ip_src.s_addr),
			(u_int32_t)ntohl(ip->ip_dst.s_addr),
			(u_int32_t)ntohl(sav->spi)));
		ipsecstat.out_inval++;
		m_freem(m);
		return EINVAL;
	}

	algo = ah_algorithm_lookup(sav->alg_auth);
	if (!algo) {
		ipseclog((LOG_ERR, "ah4_output: unsupported algorithm: "
		    "SPI=%u\n", (u_int32_t)ntohl(sav->spi)));
		ipsecstat.out_inval++;
		m_freem(m);
		return EINVAL;
	}
	spi = sav->spi;

	/*
	 * determine the size to grow.
	 */
	if (sav->flags & SADB_X_EXT_OLD) {
		/* RFC 1826 */
		plen = ((*algo->sumsiz)(sav) + 3) & ~(4 - 1); /*XXX pad to 8byte?*/
		ahlen = plen + sizeof(struct ah);
	} else {
		/* RFC 2402 */
		plen = ((*algo->sumsiz)(sav) + 3) & ~(4 - 1); /*XXX pad to 8byte?*/
		ahlen = plen + sizeof(struct newah);
	}

	/*
	 * grow the mbuf to accomodate AH.
	 */
	ip = mtod(m, struct ip *);
#ifdef _IP_VHL
	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
#else
	hlen = ip->ip_hl << 2;
#endif

	if (m->m_len != hlen)
		panic("ah4_output: assumption failed (first mbuf length)");
	if (M_LEADINGSPACE(m->m_next) < ahlen) {
		struct mbuf *n;
		MGET(n, M_DONTWAIT, MT_DATA);
		if (!n) {
			ipseclog((LOG_DEBUG, "ENOBUFS in ah4_output %d\n",
			    __LINE__));
			m_freem(m);
			return ENOBUFS;
		}
		n->m_len = ahlen;
		n->m_next = m->m_next;
		m->m_next = n;
		m->m_pkthdr.len += ahlen;
		ahdrpos = mtod(n, u_char *);
	} else {
		m->m_next->m_len += ahlen;
		m->m_next->m_data -= ahlen;
		m->m_pkthdr.len += ahlen;
		ahdrpos = mtod(m->m_next, u_char *);
	}

	ip = mtod(m, struct ip *);	/*just to be sure*/

	/*
	 * initialize AH.
	 */
	if (sav->flags & SADB_X_EXT_OLD) {
		struct ah *ahdr;

		ahdr = (struct ah *)ahdrpos;
		ahsumpos = (u_char *)(ahdr + 1);
		ahdr->ah_len = plen >> 2;
		ahdr->ah_nxt = ip->ip_p;
		ahdr->ah_reserve = htons(0);
		ahdr->ah_spi = spi;
		bzero(ahdr + 1, plen);
	} else {
		struct newah *ahdr;

		ahdr = (struct newah *)ahdrpos;
		ahsumpos = (u_char *)(ahdr + 1);
		ahdr->ah_len = (plen >> 2) + 1;	/* plus one for seq# */
		ahdr->ah_nxt = ip->ip_p;
		ahdr->ah_reserve = htons(0);
		ahdr->ah_spi = spi;
		if (sav->replay->count == ~0) {
			if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
				/* XXX Is it noisy ? */
				ipseclog((LOG_WARNING,
				    "replay counter overflowed. %s\n",
				    ipsec_logsastr(sav)));
				ipsecstat.out_inval++;
				m_freem(m);
				return EINVAL;
			}
		}
		sav->replay->count++;
		/*
		 * XXX sequence number must not be cycled, if the SA is
		 * installed by IKE daemon.
		 */
		ahdr->ah_seq = htonl(sav->replay->count);
		bzero(ahdr + 1, plen);
	}

	/*
	 * modify IPv4 header.
	 */
	ip->ip_p = IPPROTO_AH;
	if (ahlen < (IP_MAXPACKET - ntohs(ip->ip_len)))
		ip->ip_len = htons(ntohs(ip->ip_len) + ahlen);
	else {
		ipseclog((LOG_ERR, "IPv4 AH output: size exceeds limit\n"));
		ipsecstat.out_inval++;
		m_freem(m);
		return EMSGSIZE;
	}

	/*
	 * If there is source routing option, update destination field in
	 * the IPv4 header to the final destination.
	 * Note that we do not need to update source routing option itself
	 * (as done in IPv4 AH processing -- see ip6_output()), since
	 * source routing option is not part of the ICV computation.
	 */
	finaldst = ah4_finaldst(m);
	if (finaldst) {
		dst.s_addr = ip->ip_dst.s_addr;
		ip->ip_dst.s_addr = finaldst->s_addr;
	}

	/*
	 * calcurate the checksum, based on security association
	 * and the algorithm specified.
	 */
	error = ah4_calccksum(m, (caddr_t)ahsumpos, plen, algo, sav);
	if (error) {
		ipseclog((LOG_ERR,
		    "error after ah4_calccksum, called from ah4_output"));
		m_freem(m);
		m = NULL;
		ipsecstat.out_inval++;
		return error;
	}

	if (finaldst) {
		ip = mtod(m, struct ip *);	/*just to make sure*/
		ip->ip_dst.s_addr = dst.s_addr;
	}
	ipsecstat.out_success++;
	ipsecstat.out_ahhist[sav->alg_auth]++;
	key_sa_recordxfer(sav, m);

	return 0;
}
#endif

/* Calculate AH length */
int
ah_hdrlen(sav)
	struct secasvar *sav;
{
	const struct ah_algorithm *algo;
	int plen, ahlen;
	
	algo = ah_algorithm_lookup(sav->alg_auth);
	if (!algo)
		return 0;
	if (sav->flags & SADB_X_EXT_OLD) {
		/* RFC 1826 */
		plen = ((*algo->sumsiz)(sav) + 3) & ~(4 - 1);	/*XXX pad to 8byte?*/
		ahlen = plen + sizeof(struct ah);
	} else {
		/* RFC 2402 */
		plen = ((*algo->sumsiz)(sav) + 3) & ~(4 - 1);	/*XXX pad to 8byte?*/
		ahlen = plen + sizeof(struct newah);
	}

	return(ahlen);
}

#if INET6
/*
 * Fill in the Authentication Header and calculate checksum.
 */
int
ah6_output(m, nexthdrp, md, isr)
	struct mbuf *m;
	u_char *nexthdrp;
	struct mbuf *md;
	struct ipsecrequest *isr;
{
	struct mbuf *mprev;
	struct mbuf *mah;
	struct secasvar *sav = isr->sav;
	const struct ah_algorithm *algo;
	u_int32_t spi;
	u_char *ahsumpos = NULL;
	size_t plen;	/*AH payload size in bytes*/
	int error = 0;
	int ahlen;
	struct ip6_hdr *ip6;

	if (m->m_len < sizeof(struct ip6_hdr)) {
		ipseclog((LOG_DEBUG, "ah6_output: first mbuf too short\n"));
		m_freem(m);
		return EINVAL;
	}

	ahlen = ah_hdrlen(sav);
	if (ahlen == 0)
		return 0;

	for (mprev = m; mprev && mprev->m_next != md; mprev = mprev->m_next)
		;
	if (!mprev || mprev->m_next != md) {
		ipseclog((LOG_DEBUG, "ah6_output: md is not in chain\n"));
		m_freem(m);
		return EINVAL;
	}

	MGET(mah, M_DONTWAIT, MT_DATA);
	if (!mah) {
		m_freem(m);
		return ENOBUFS;
	}
	if (ahlen > MLEN) {
		MCLGET(mah, M_DONTWAIT);
		if ((mah->m_flags & M_EXT) == 0) {
			m_free(mah);
			m_freem(m);
			return ENOBUFS;
		}
	}
	mah->m_len = ahlen;
	mah->m_next = md;
	mprev->m_next = mah;
	m->m_pkthdr.len += ahlen;

	/* fix plen */
	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) > IPV6_MAXPACKET) {
		ipseclog((LOG_ERR,
		    "ip6_output: AH with IPv6 jumbogram is not supported\n"));
		m_freem(m);
		return EINVAL;
	}
	ip6 = mtod(m, struct ip6_hdr *);
	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));

	if ((sav->flags & SADB_X_EXT_OLD) == 0 && !sav->replay) {
		ipseclog((LOG_DEBUG, "ah6_output: internal error: "
			"sav->replay is null: SPI=%u\n",
			(u_int32_t)ntohl(sav->spi)));
		ipsec6stat.out_inval++;
		m_freem(m);
		return EINVAL;
	}

	algo = ah_algorithm_lookup(sav->alg_auth);
	if (!algo) {
		ipseclog((LOG_ERR, "ah6_output: unsupported algorithm: "
		    "SPI=%u\n", (u_int32_t)ntohl(sav->spi)));
		ipsec6stat.out_inval++;
		m_freem(m);
		return EINVAL;
	}
	spi = sav->spi;

	/*
	 * initialize AH.
	 */
	if (sav->flags & SADB_X_EXT_OLD) {
		struct ah *ahdr = mtod(mah, struct ah *);

		plen = mah->m_len - sizeof(struct ah);
		ahsumpos = (u_char *)(ahdr + 1);
		ahdr->ah_nxt = *nexthdrp;
		*nexthdrp = IPPROTO_AH;
		ahdr->ah_len = plen >> 2;
		ahdr->ah_reserve = htons(0);
		ahdr->ah_spi = spi;
		bzero(ahdr + 1, plen);
	} else {
		struct newah *ahdr = mtod(mah, struct newah *);

		plen = mah->m_len - sizeof(struct newah);
		ahsumpos = (u_char *)(ahdr + 1);
		ahdr->ah_nxt = *nexthdrp;
		*nexthdrp = IPPROTO_AH;
		ahdr->ah_len = (plen >> 2) + 1;	/* plus one for seq# */
		ahdr->ah_reserve = htons(0);
		ahdr->ah_spi = spi;
		if (sav->replay->count == ~0) {
			if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
				/* XXX Is it noisy ? */
				ipseclog((LOG_WARNING,
				    "replay counter overflowed. %s\n",
				    ipsec_logsastr(sav)));
				ipsec6stat.out_inval++;
				m_freem(m);
				return EINVAL;
			}
		}
		sav->replay->count++;
		/*
		 * XXX sequence number must not be cycled, if the SA is
		 * installed by IKE daemon.
		 */
		ahdr->ah_seq = htonl(sav->replay->count);
		bzero(ahdr + 1, plen);
	}

	/*
	 * calcurate the checksum, based on security association
	 * and the algorithm specified.
	 */
	error = ah6_calccksum(m, (caddr_t)ahsumpos, plen, algo, sav);
	if (error) {
		ipsec6stat.out_inval++;
		m_freem(m);
	} else {
		ipsec6stat.out_success++;
		key_sa_recordxfer(sav, m);
	}
	ipsec6stat.out_ahhist[sav->alg_auth]++;

	return(error);
}
#endif

#if INET
/*
 * Find the final destination if there is loose/strict source routing option.
 * Returns NULL if there's no source routing options.
 * Returns NULL on errors too.
 * Note that this function will return a pointer INTO the given parameter,
 * struct mbuf *m.
 * The mbuf must be pulled up toward, at least, ip option part.
 */
static struct in_addr *
ah4_finaldst(m)
	struct mbuf *m;
{
	struct ip *ip;
	int optlen;
	u_char *q;
	int i;
	int hlen;

	if (!m)
		panic("ah4_finaldst: m == NULL");
	ip = mtod(m, struct ip *);
#ifdef _IP_VHL
	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
#else
	hlen = ip->ip_hl << 2;
#endif

	if (m->m_len < hlen) {
		ipseclog((LOG_DEBUG,
		    "ah4_finaldst: parameter mbuf wrong (not pulled up)\n"));
		return NULL;
	}

	if (hlen == sizeof(struct ip))
		return NULL;

	optlen = hlen - sizeof(struct ip);
	if (optlen < 0) {
		ipseclog((LOG_DEBUG, "ah4_finaldst: wrong optlen %d\n",
		    optlen));
		return NULL;
	}

	q = (u_char *)(ip + 1);
	i = 0;
	while (i < optlen) {
		if (i + IPOPT_OPTVAL >= optlen)
			return NULL;
		if (q[i + IPOPT_OPTVAL] == IPOPT_EOL ||
		    q[i + IPOPT_OPTVAL] == IPOPT_NOP ||
		    i + IPOPT_OLEN < optlen)
			;
		else
			return NULL;

		switch (q[i + IPOPT_OPTVAL]) {
		case IPOPT_EOL:
			i = optlen;	/* bye */
			break;
		case IPOPT_NOP:
			i++;
			break;
		case IPOPT_LSRR:
		case IPOPT_SSRR:
			if (q[i + IPOPT_OLEN] < 2 + sizeof(struct in_addr) ||
			    optlen - i < q[i + IPOPT_OLEN]) {
				ipseclog((LOG_ERR,
				    "ip_finaldst: invalid IP option "
				    "(code=%02x len=%02x)\n",
				    q[i + IPOPT_OPTVAL], q[i + IPOPT_OLEN]));
				return NULL;
			}
			i += q[i + IPOPT_OLEN] - sizeof(struct in_addr);
			return (struct in_addr *)(q + i);
		default:
			if (q[i + IPOPT_OLEN] < 2 ||
			    optlen - i < q[i + IPOPT_OLEN]) {
				ipseclog((LOG_ERR,
				    "ip_finaldst: invalid IP option "
				    "(code=%02x len=%02x)\n",
				    q[i + IPOPT_OPTVAL], q[i + IPOPT_OLEN]));
				return NULL;
			}
			i += q[i + IPOPT_OLEN];
			break;
		}
	}
	return NULL;
}
#endif
Commit	Line	Data
9bccf70c A	1	/* $FreeBSD: src/sys/netinet6/ah_output.c,v 1.1.2.3 2001/07/03 11:01:49 ume Exp $ */
9bccf70c A	2	/* $KAME: ah_output.c,v 1.30 2001/02/21 00:50:53 itojun Exp $ */
1c79356b A	3
	4	/*
	5	* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
	6	* All rights reserved.
	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	* 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. Neither the name of the project nor the names of its contributors
	17	* may be used to endorse or promote products derived from this software
	18	* without specific prior written permission.
	19	*
	20	* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
	21	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
	24	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	* SUCH DAMAGE.
	31	*/
	32
	33	/*
	34	* RFC1826/2402 authentication header.
	35	*/
	36
	37	#define _IP_VHL
1c79356b A	38
	39	#include <sys/param.h>
	40	#include <sys/systm.h>
	41	#include <sys/malloc.h>
	42	#include <sys/mbuf.h>
	43	#include <sys/domain.h>
	44	#include <sys/protosw.h>
	45	#include <sys/socket.h>
	46	#include <sys/socketvar.h>
	47	#include <sys/errno.h>
	48	#include <sys/time.h>
	49	#include <sys/kernel.h>
	50	#include <sys/syslog.h>
	51
	52	#include <net/if.h>
	53	#include <net/route.h>
	54
	55	#include <netinet/in.h>
	56
	57	#include <netinet/in_systm.h>
	58	#include <netinet/ip.h>
	59	#include <netinet/in_var.h>
	60
	61	#if INET6
	62	#include <netinet/ip6.h>
	63	#include <netinet6/ip6_var.h>
	64	#include <netinet/icmp6.h>
	65	#endif
	66
	67	#include <netinet6/ipsec.h>
9bccf70c A	68	#if INET6
	69	#include <netinet6/ipsec6.h>
	70	#endif
1c79356b	71	#include <netinet6/ah.h>
9bccf70c A	72	#if INET6
	73	#include <netinet6/ah6.h>
	74	#endif
1c79356b A	75	#include <netkey/key.h>
1c79356b A	76	#include <netkey/keydb.h>
1c79356b A	77
	78	#include <net/net_osdep.h>
	79
9bccf70c	80	#if INET
1c79356b	81	static struct in_addr ah4_finaldst __P((struct mbuf ));
9bccf70c	82	#endif
1c79356b A	83
	84	/*
	85	* compute AH header size.
	86	* transport mode only. for tunnel mode, we should implement
	87	* virtual interface, and control MTU/MSS by the interface MTU.
	88	*/
	89	size_t
	90	ah_hdrsiz(isr)
	91	struct ipsecrequest *isr;
	92	{
9bccf70c	93	const struct ah_algorithm *algo;
1c79356b A	94	size_t hdrsiz;
	95
	96	/* sanity check */
	97	if (isr == NULL)
	98	panic("ah_hdrsiz: NULL was passed.\n");
	99
	100	if (isr->saidx.proto != IPPROTO_AH)
	101	panic("unsupported mode passed to ah_hdrsiz");
	102
	103	if (isr->sav == NULL)
	104	goto estimate;
	105	if (isr->sav->state != SADB_SASTATE_MATURE
	106	&& isr->sav->state != SADB_SASTATE_DYING)
	107	goto estimate;
	108
	109	/* we need transport mode AH. */
9bccf70c	110	algo = ah_algorithm_lookup(isr->sav->alg_auth);
1c79356b A	111	if (!algo)
	112	goto estimate;
	113
	114	/*
	115	* XXX
	116	* right now we don't calcurate the padding size. simply
	117	* treat the padding size as constant, for simplicity.
	118	*
	119	* XXX variable size padding support
	120	*/
	121	hdrsiz = (((*algo->sumsiz)(isr->sav) + 3) & ~(4 - 1));
	122	if (isr->sav->flags & SADB_X_EXT_OLD)
	123	hdrsiz += sizeof(struct ah);
	124	else
	125	hdrsiz += sizeof(struct newah);
	126
	127	return hdrsiz;
	128
	129	estimate:
	130	/* ASSUMING:
	131	* sizeof(struct newah) > sizeof(struct ah).
	132	* 16 = (16 + 3) & ~(4 - 1).
	133	*/
	134	return sizeof(struct newah) + 16;
	135	}
	136
9bccf70c	137	#if INET
1c79356b A	138	/*
	139	* Modify the packet so that it includes the authentication data.
	140	* The mbuf passed must start with IPv4 header.
	141	*
	142	* assumes that the first mbuf contains IPv4 header + option only.
	143	* the function does not modify m.
	144	*/
	145	int
	146	ah4_output(m, isr)
	147	struct mbuf *m;
	148	struct ipsecrequest *isr;
	149	{
	150	struct secasvar *sav = isr->sav;
9bccf70c	151	const struct ah_algorithm *algo;
1c79356b A	152	u_int32_t spi;
	153	u_char *ahdrpos;
	154	u_char *ahsumpos = NULL;
	155	size_t hlen = 0; /IP header+option in bytes/
	156	size_t plen = 0; /AH payload size in bytes/
	157	size_t ahlen = 0; /plen + sizeof(ah)/
	158	struct ip *ip;
	159	struct in_addr dst;
	160	struct in_addr *finaldst;
	161	int error;
	162
	163	/* sanity checks */
	164	if ((sav->flags & SADB_X_EXT_OLD) == 0 && !sav->replay) {
	165	struct ip *ip;
	166
	167	ip = mtod(m, struct ip *);
	168	ipseclog((LOG_DEBUG, "ah4_output: internal error: "
	169	"sav->replay is null: %x->%x, SPI=%u\n",
	170	(u_int32_t)ntohl(ip->ip_src.s_addr),
	171	(u_int32_t)ntohl(ip->ip_dst.s_addr),
	172	(u_int32_t)ntohl(sav->spi)));
	173	ipsecstat.out_inval++;
	174	m_freem(m);
	175	return EINVAL;
	176	}
	177
9bccf70c A	178	algo = ah_algorithm_lookup(sav->alg_auth);
	179	if (!algo) {
	180	ipseclog((LOG_ERR, "ah4_output: unsupported algorithm: "
	181	"SPI=%u\n", (u_int32_t)ntohl(sav->spi)));
	182	ipsecstat.out_inval++;
	183	m_freem(m);
	184	return EINVAL;
	185	}
1c79356b A	186	spi = sav->spi;
	187
	188	/*
	189	* determine the size to grow.
	190	*/
	191	if (sav->flags & SADB_X_EXT_OLD) {
	192	/* RFC 1826 */
	193	plen = ((algo->sumsiz)(sav) + 3) & ~(4 - 1); /XXX pad to 8byte?*/
	194	ahlen = plen + sizeof(struct ah);
	195	} else {
	196	/* RFC 2402 */
	197	plen = ((algo->sumsiz)(sav) + 3) & ~(4 - 1); /XXX pad to 8byte?*/
	198	ahlen = plen + sizeof(struct newah);
	199	}
	200
	201	/*
	202	* grow the mbuf to accomodate AH.
	203	*/
	204	ip = mtod(m, struct ip *);
	205	#ifdef _IP_VHL
	206	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
	207	#else
	208	hlen = ip->ip_hl << 2;
	209	#endif
	210
	211	if (m->m_len != hlen)
	212	panic("ah4_output: assumption failed (first mbuf length)");
	213	if (M_LEADINGSPACE(m->m_next) < ahlen) {
	214	struct mbuf *n;
	215	MGET(n, M_DONTWAIT, MT_DATA);
	216	if (!n) {
	217	ipseclog((LOG_DEBUG, "ENOBUFS in ah4_output %d\n",
	218	__LINE__));
	219	m_freem(m);
	220	return ENOBUFS;
	221	}
	222	n->m_len = ahlen;
	223	n->m_next = m->m_next;
	224	m->m_next = n;
	225	m->m_pkthdr.len += ahlen;
	226	ahdrpos = mtod(n, u_char *);
	227	} else {
	228	m->m_next->m_len += ahlen;
	229	m->m_next->m_data -= ahlen;
	230	m->m_pkthdr.len += ahlen;
	231	ahdrpos = mtod(m->m_next, u_char *);
	232	}
	233
	234	ip = mtod(m, struct ip ); /just to be sure*/
	235
	236	/*
	237	* initialize AH.
	238	*/
	239	if (sav->flags & SADB_X_EXT_OLD) {
	240	struct ah *ahdr;
	241
	242	ahdr = (struct ah *)ahdrpos;
	243	ahsumpos = (u_char *)(ahdr + 1);
	244	ahdr->ah_len = plen >> 2;
	245	ahdr->ah_nxt = ip->ip_p;
	246	ahdr->ah_reserve = htons(0);
	247	ahdr->ah_spi = spi;
	248	bzero(ahdr + 1, plen);
	249	} else {
250	struct newah *ahdr;
251
252	ahdr = (struct newah *)ahdrpos;
253	ahsumpos = (u_char *)(ahdr + 1);
254	ahdr->ah_len = (plen >> 2) + 1; /* plus one for seq# */
255	ahdr->ah_nxt = ip->ip_p;
256	ahdr->ah_reserve = htons(0);
257	ahdr->ah_spi = spi;
258	if (sav->replay->count == ~0) {
259	if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
260	/* XXX Is it noisy ? */
261	ipseclog((LOG_WARNING,
262	"replay counter overflowed. %s\n",
263	ipsec_logsastr(sav)));
264	ipsecstat.out_inval++;
265	m_freem(m);
266	return EINVAL;
267	}
268	}
269	sav->replay->count++;
270	/*
271	* XXX sequence number must not be cycled, if the SA is
272	* installed by IKE daemon.
273	*/
274	ahdr->ah_seq = htonl(sav->replay->count);
275	bzero(ahdr + 1, plen);
276	}
277
278	/*
279	* modify IPv4 header.
280	*/
281	ip->ip_p = IPPROTO_AH;
282	if (ahlen < (IP_MAXPACKET - ntohs(ip->ip_len)))
283	ip->ip_len = htons(ntohs(ip->ip_len) + ahlen);
284	else {
285	ipseclog((LOG_ERR, "IPv4 AH output: size exceeds limit\n"));
286	ipsecstat.out_inval++;
287	m_freem(m);
288	return EMSGSIZE;
289	}
290
291	/*
292	* If there is source routing option, update destination field in
293	* the IPv4 header to the final destination.
294	* Note that we do not need to update source routing option itself
295	* (as done in IPv4 AH processing -- see ip6_output()), since
296	* source routing option is not part of the ICV computation.
297	*/
298	finaldst = ah4_finaldst(m);
299	if (finaldst) {
300	dst.s_addr = ip->ip_dst.s_addr;
301	ip->ip_dst.s_addr = finaldst->s_addr;
302	}
303
304	/*
305	* calcurate the checksum, based on security association
306	* and the algorithm specified.
307	*/
9bccf70c	308	error = ah4_calccksum(m, (caddr_t)ahsumpos, plen, algo, sav);
1c79356b A	309	if (error) {
	310	ipseclog((LOG_ERR,
	311	"error after ah4_calccksum, called from ah4_output"));
9bccf70c	312	m_freem(m);
1c79356b A	313	m = NULL;
	314	ipsecstat.out_inval++;
	315	return error;
	316	}
	317
	318	if (finaldst) {
	319	ip = mtod(m, struct ip ); /just to make sure*/
	320	ip->ip_dst.s_addr = dst.s_addr;
	321	}
	322	ipsecstat.out_success++;
	323	ipsecstat.out_ahhist[sav->alg_auth]++;
	324	key_sa_recordxfer(sav, m);
	325
	326	return 0;
	327	}
9bccf70c	328	#endif
1c79356b A	329
	330	/* Calculate AH length */
	331	int
	332	ah_hdrlen(sav)
	333	struct secasvar *sav;
	334	{
9bccf70c	335	const struct ah_algorithm *algo;
1c79356b A	336	int plen, ahlen;
1c79356b A	337
9bccf70c A	338	algo = ah_algorithm_lookup(sav->alg_auth);
	339	if (!algo)
	340	return 0;
1c79356b A	341	if (sav->flags & SADB_X_EXT_OLD) {
	342	/* RFC 1826 */
	343	plen = ((algo->sumsiz)(sav) + 3) & ~(4 - 1); /XXX pad to 8byte?*/
	344	ahlen = plen + sizeof(struct ah);
	345	} else {
	346	/* RFC 2402 */
	347	plen = ((algo->sumsiz)(sav) + 3) & ~(4 - 1); /XXX pad to 8byte?*/
	348	ahlen = plen + sizeof(struct newah);
	349	}
	350
	351	return(ahlen);
	352	}
	353
	354	#if INET6
	355	/*
	356	* Fill in the Authentication Header and calculate checksum.
	357	*/
	358	int
	359	ah6_output(m, nexthdrp, md, isr)
	360	struct mbuf *m;
	361	u_char *nexthdrp;
	362	struct mbuf *md;
	363	struct ipsecrequest *isr;
	364	{
	365	struct mbuf *mprev;
	366	struct mbuf *mah;
	367	struct secasvar *sav = isr->sav;
9bccf70c	368	const struct ah_algorithm *algo;
1c79356b A	369	u_int32_t spi;
	370	u_char *ahsumpos = NULL;
	371	size_t plen; /AH payload size in bytes/
	372	int error = 0;
	373	int ahlen;
	374	struct ip6_hdr *ip6;
	375
	376	if (m->m_len < sizeof(struct ip6_hdr)) {
	377	ipseclog((LOG_DEBUG, "ah6_output: first mbuf too short\n"));
	378	m_freem(m);
	379	return EINVAL;
	380	}
	381
	382	ahlen = ah_hdrlen(sav);
	383	if (ahlen == 0)
	384	return 0;
	385
	386	for (mprev = m; mprev && mprev->m_next != md; mprev = mprev->m_next)
	387	;
	388	if (!mprev \|\| mprev->m_next != md) {
	389	ipseclog((LOG_DEBUG, "ah6_output: md is not in chain\n"));
	390	m_freem(m);
	391	return EINVAL;
	392	}
	393
	394	MGET(mah, M_DONTWAIT, MT_DATA);
	395	if (!mah) {
	396	m_freem(m);
	397	return ENOBUFS;
	398	}
	399	if (ahlen > MLEN) {
	400	MCLGET(mah, M_DONTWAIT);
	401	if ((mah->m_flags & M_EXT) == 0) {
	402	m_free(mah);
	403	m_freem(m);
	404	return ENOBUFS;
	405	}
	406	}
	407	mah->m_len = ahlen;
	408	mah->m_next = md;
	409	mprev->m_next = mah;
	410	m->m_pkthdr.len += ahlen;
	411
	412	/* fix plen */
	413	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) > IPV6_MAXPACKET) {
	414	ipseclog((LOG_ERR,
	415	"ip6_output: AH with IPv6 jumbogram is not supported\n"));
	416	m_freem(m);
	417	return EINVAL;
	418	}
	419	ip6 = mtod(m, struct ip6_hdr *);
	420	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
	421
	422	if ((sav->flags & SADB_X_EXT_OLD) == 0 && !sav->replay) {
	423	ipseclog((LOG_DEBUG, "ah6_output: internal error: "
	424	"sav->replay is null: SPI=%u\n",
	425	(u_int32_t)ntohl(sav->spi)));
	426	ipsec6stat.out_inval++;
	427	m_freem(m);
	428	return EINVAL;
	429	}
	430
9bccf70c A	431	algo = ah_algorithm_lookup(sav->alg_auth);
	432	if (!algo) {
	433	ipseclog((LOG_ERR, "ah6_output: unsupported algorithm: "
	434	"SPI=%u\n", (u_int32_t)ntohl(sav->spi)));
	435	ipsec6stat.out_inval++;
	436	m_freem(m);
	437	return EINVAL;
	438	}
1c79356b A	439	spi = sav->spi;
	440
	441	/*
	442	* initialize AH.
	443	*/
	444	if (sav->flags & SADB_X_EXT_OLD) {
	445	struct ah ahdr = mtod(mah, struct ah );
	446
	447	plen = mah->m_len - sizeof(struct ah);
	448	ahsumpos = (u_char *)(ahdr + 1);
	449	ahdr->ah_nxt = *nexthdrp;
	450	*nexthdrp = IPPROTO_AH;
	451	ahdr->ah_len = plen >> 2;
	452	ahdr->ah_reserve = htons(0);
	453	ahdr->ah_spi = spi;
	454	bzero(ahdr + 1, plen);
	455	} else {
	456	struct newah ahdr = mtod(mah, struct newah );
	457
	458	plen = mah->m_len - sizeof(struct newah);
	459	ahsumpos = (u_char *)(ahdr + 1);
	460	ahdr->ah_nxt = *nexthdrp;
	461	*nexthdrp = IPPROTO_AH;
	462	ahdr->ah_len = (plen >> 2) + 1; /* plus one for seq# */
	463	ahdr->ah_reserve = htons(0);
	464	ahdr->ah_spi = spi;
	465	if (sav->replay->count == ~0) {
	466	if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
	467	/* XXX Is it noisy ? */
	468	ipseclog((LOG_WARNING,
	469	"replay counter overflowed. %s\n",
	470	ipsec_logsastr(sav)));
9bccf70c	471	ipsec6stat.out_inval++;
1c79356b A	472	m_freem(m);
	473	return EINVAL;
	474	}
	475	}
	476	sav->replay->count++;
	477	/*
	478	* XXX sequence number must not be cycled, if the SA is
	479	* installed by IKE daemon.
	480	*/
	481	ahdr->ah_seq = htonl(sav->replay->count);
	482	bzero(ahdr + 1, plen);
	483	}
	484
	485	/*
	486	* calcurate the checksum, based on security association
	487	* and the algorithm specified.
	488	*/
9bccf70c	489	error = ah6_calccksum(m, (caddr_t)ahsumpos, plen, algo, sav);
1c79356b A	490	if (error) {
	491	ipsec6stat.out_inval++;
	492	m_freem(m);
	493	} else {
	494	ipsec6stat.out_success++;
	495	key_sa_recordxfer(sav, m);
	496	}
	497	ipsec6stat.out_ahhist[sav->alg_auth]++;
	498
	499	return(error);
	500	}
	501	#endif
	502
9bccf70c	503	#if INET
1c79356b A	504	/*
	505	* Find the final destination if there is loose/strict source routing option.
	506	* Returns NULL if there's no source routing options.
	507	* Returns NULL on errors too.
	508	* Note that this function will return a pointer INTO the given parameter,
	509	* struct mbuf *m.
	510	* The mbuf must be pulled up toward, at least, ip option part.
	511	*/
	512	static struct in_addr *
	513	ah4_finaldst(m)
	514	struct mbuf *m;
	515	{
	516	struct ip *ip;
	517	int optlen;
	518	u_char *q;
	519	int i;
	520	int hlen;
	521
	522	if (!m)
	523	panic("ah4_finaldst: m == NULL");
	524	ip = mtod(m, struct ip *);
	525	#ifdef _IP_VHL
	526	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
	527	#else
	528	hlen = ip->ip_hl << 2;
	529	#endif
	530
	531	if (m->m_len < hlen) {
	532	ipseclog((LOG_DEBUG,
	533	"ah4_finaldst: parameter mbuf wrong (not pulled up)\n"));
	534	return NULL;
	535	}
	536
	537	if (hlen == sizeof(struct ip))
	538	return NULL;
	539
	540	optlen = hlen - sizeof(struct ip);
	541	if (optlen < 0) {
	542	ipseclog((LOG_DEBUG, "ah4_finaldst: wrong optlen %d\n",
	543	optlen));
	544	return NULL;
	545	}
	546
	547	q = (u_char *)(ip + 1);
	548	i = 0;
	549	while (i < optlen) {
9bccf70c A	550	if (i + IPOPT_OPTVAL >= optlen)
	551	return NULL;
	552	if (q[i + IPOPT_OPTVAL] == IPOPT_EOL \|\|
	553	q[i + IPOPT_OPTVAL] == IPOPT_NOP \|\|
	554	i + IPOPT_OLEN < optlen)
	555	;
	556	else
	557	return NULL;
	558
1c79356b A	559	switch (q[i + IPOPT_OPTVAL]) {
	560	case IPOPT_EOL:
	561	i = optlen; /* bye */
	562	break;
	563	case IPOPT_NOP:
	564	i++;
	565	break;
	566	case IPOPT_LSRR:
	567	case IPOPT_SSRR:
9bccf70c A	568	if (q[i + IPOPT_OLEN] < 2 + sizeof(struct in_addr) \|\|
9bccf70c A	569	optlen - i < q[i + IPOPT_OLEN]) {
1c79356b A	570	ipseclog((LOG_ERR,
	571	"ip_finaldst: invalid IP option "
	572	"(code=%02x len=%02x)\n",
	573	q[i + IPOPT_OPTVAL], q[i + IPOPT_OLEN]));
	574	return NULL;
	575	}
	576	i += q[i + IPOPT_OLEN] - sizeof(struct in_addr);
	577	return (struct in_addr *)(q + i);
	578	default:
9bccf70c A	579	if (q[i + IPOPT_OLEN] < 2 \|\|
9bccf70c A	580	optlen - i < q[i + IPOPT_OLEN]) {
1c79356b A	581	ipseclog((LOG_ERR,
	582	"ip_finaldst: invalid IP option "
	583	"(code=%02x len=%02x)\n",
	584	q[i + IPOPT_OPTVAL], q[i + IPOPT_OLEN]));
	585	return NULL;
	586	}
	587	i += q[i + IPOPT_OLEN];
	588	break;
	589	}
	590	}
	591	return NULL;
	592	}
9bccf70c	593	#endif