[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(struct mbuf *);
#endif

extern lck_mtx_t *sadb_mutex;

/*
 * 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;
{

	/* 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 0
	{

		lck_mtx_lock(sadb_mutex);
		const struct ah_algorithm *algo;
		size_t hdrsiz;

		/*%%%%% this needs to change - no sav in ipsecrequest any more */
		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);
	
		lck_mtx_unlock(sadb_mutex);
		return hdrsiz;
	}

estimate:
#endif

    //lck_mtx_unlock(sadb_mutex);
	/* 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, sav)
	struct mbuf *m;
	struct secasvar *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 = { 0 };
	struct in_addr *finaldst;
	int error;

	/* sanity checks */
	if ((sav->flags & SADB_X_EXT_OLD) == 0 && !sav->replay) {
		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)));
		IPSEC_STAT_INCREMENT(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)));
		IPSEC_STAT_INCREMENT(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)));
				IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
				m_freem(m);
				return EINVAL;
			}
		}
		lck_mtx_lock(sadb_mutex);
		sav->replay->count++;
		lck_mtx_unlock(sadb_mutex);
		/*
		 * 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"));
		IPSEC_STAT_INCREMENT(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;
		IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
		return error;
	}

	if (finaldst) {
		ip = mtod(m, struct ip *);	/*just to make sure*/
		ip->ip_dst.s_addr = dst.s_addr;
	}
	lck_mtx_lock(sadb_stat_mutex);
	ipsecstat.out_success++;
	ipsecstat.out_ahhist[sav->alg_auth]++;
	lck_mtx_unlock(sadb_stat_mutex);
	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, sav)
	struct mbuf *m;
	u_char *nexthdrp;
	struct mbuf *md;
	struct secasvar *sav;
{
	struct mbuf *mprev;
	struct mbuf *mah;
	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)));
		IPSEC_STAT_INCREMENT(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)));
		IPSEC_STAT_INCREMENT(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)));
				IPSEC_STAT_INCREMENT(ipsec6stat.out_inval);
				m_freem(m);
				return EINVAL;
			}
		}
		lck_mtx_lock(sadb_mutex);
		sav->replay->count++;
		lck_mtx_unlock(sadb_mutex);
		/*
		 * 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) {
		IPSEC_STAT_INCREMENT(ipsec6stat.out_inval);
		m_freem(m);
	} else {
		IPSEC_STAT_INCREMENT(ipsec6stat.out_success);
		key_sa_recordxfer(sav, m);
	}
	IPSEC_STAT_INCREMENT(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
91447636	81	static struct in_addr ah4_finaldst(struct mbuf );
9bccf70c	82	#endif
1c79356b	83
2d21ac55 A	84	extern lck_mtx_t *sadb_mutex;
2d21ac55 A	85
1c79356b A	86	/*
	87	* compute AH header size.
	88	* transport mode only. for tunnel mode, we should implement
	89	* virtual interface, and control MTU/MSS by the interface MTU.
	90	*/
	91	size_t
	92	ah_hdrsiz(isr)
	93	struct ipsecrequest *isr;
	94	{
1c79356b A	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
2d21ac55 A	103	#if 0
2d21ac55 A	104	{
1c79356b	105
2d21ac55 A	106	lck_mtx_lock(sadb_mutex);
	107	const struct ah_algorithm *algo;
	108	size_t hdrsiz;
1c79356b	109
2d21ac55 A	110	/%%%%% this needs to change - no sav in ipsecrequest any more /
	111	if (isr->sav == NULL)
	112	goto estimate;
	113	if (isr->sav->state != SADB_SASTATE_MATURE
	114	&& isr->sav->state != SADB_SASTATE_DYING)
	115	goto estimate;
	116
	117	/* we need transport mode AH. */
	118	algo = ah_algorithm_lookup(isr->sav->alg_auth);
	119	if (!algo)
	120	goto estimate;
	121
	122	/*
	123	* XXX
	124	* right now we don't calcurate the padding size. simply
	125	* treat the padding size as constant, for simplicity.
	126	*
	127	* XXX variable size padding support
	128	*/
	129	hdrsiz = (((*algo->sumsiz)(isr->sav) + 3) & ~(4 - 1));
	130	if (isr->sav->flags & SADB_X_EXT_OLD)
	131	hdrsiz += sizeof(struct ah);
	132	else
	133	hdrsiz += sizeof(struct newah);
	134
	135	lck_mtx_unlock(sadb_mutex);
	136	return hdrsiz;
	137	}
1c79356b	138
2d21ac55 A	139	estimate:
2d21ac55 A	140	#endif
1c79356b	141
2d21ac55	142	//lck_mtx_unlock(sadb_mutex);
1c79356b A	143	/* ASSUMING:
	144	* sizeof(struct newah) > sizeof(struct ah).
	145	* 16 = (16 + 3) & ~(4 - 1).
	146	*/
	147	return sizeof(struct newah) + 16;
	148	}
	149
9bccf70c	150	#if INET
1c79356b A	151	/*
	152	* Modify the packet so that it includes the authentication data.
	153	* The mbuf passed must start with IPv4 header.
	154	*
	155	* assumes that the first mbuf contains IPv4 header + option only.
	156	* the function does not modify m.
	157	*/
	158	int
2d21ac55	159	ah4_output(m, sav)
1c79356b	160	struct mbuf *m;
2d21ac55	161	struct secasvar *sav;
1c79356b	162	{
9bccf70c	163	const struct ah_algorithm *algo;
1c79356b A	164	u_int32_t spi;
	165	u_char *ahdrpos;
	166	u_char *ahsumpos = NULL;
	167	size_t hlen = 0; /IP header+option in bytes/
	168	size_t plen = 0; /AH payload size in bytes/
	169	size_t ahlen = 0; /plen + sizeof(ah)/
	170	struct ip *ip;
2d21ac55	171	struct in_addr dst = { 0 };
1c79356b A	172	struct in_addr *finaldst;
	173	int error;
	174
	175	/* sanity checks */
	176	if ((sav->flags & SADB_X_EXT_OLD) == 0 && !sav->replay) {
1c79356b A	177	ip = mtod(m, struct ip *);
	178	ipseclog((LOG_DEBUG, "ah4_output: internal error: "
	179	"sav->replay is null: %x->%x, SPI=%u\n",
	180	(u_int32_t)ntohl(ip->ip_src.s_addr),
	181	(u_int32_t)ntohl(ip->ip_dst.s_addr),
	182	(u_int32_t)ntohl(sav->spi)));
2d21ac55	183	IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
1c79356b A	184	m_freem(m);
	185	return EINVAL;
	186	}
	187
9bccf70c A	188	algo = ah_algorithm_lookup(sav->alg_auth);
	189	if (!algo) {
	190	ipseclog((LOG_ERR, "ah4_output: unsupported algorithm: "
	191	"SPI=%u\n", (u_int32_t)ntohl(sav->spi)));
2d21ac55	192	IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
9bccf70c A	193	m_freem(m);
	194	return EINVAL;
	195	}
1c79356b A	196	spi = sav->spi;
	197
	198	/*
	199	* determine the size to grow.
	200	*/
	201	if (sav->flags & SADB_X_EXT_OLD) {
	202	/* RFC 1826 */
	203	plen = ((algo->sumsiz)(sav) + 3) & ~(4 - 1); /XXX pad to 8byte?*/
	204	ahlen = plen + sizeof(struct ah);
	205	} else {
	206	/* RFC 2402 */
	207	plen = ((algo->sumsiz)(sav) + 3) & ~(4 - 1); /XXX pad to 8byte?*/
	208	ahlen = plen + sizeof(struct newah);
	209	}
	210
	211	/*
	212	* grow the mbuf to accomodate AH.
	213	*/
	214	ip = mtod(m, struct ip *);
	215	#ifdef _IP_VHL
	216	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
	217	#else
	218	hlen = ip->ip_hl << 2;
	219	#endif
	220
	221	if (m->m_len != hlen)
	222	panic("ah4_output: assumption failed (first mbuf length)");
	223	if (M_LEADINGSPACE(m->m_next) < ahlen) {
	224	struct mbuf *n;
	225	MGET(n, M_DONTWAIT, MT_DATA);
	226	if (!n) {
	227	ipseclog((LOG_DEBUG, "ENOBUFS in ah4_output %d\n",
	228	__LINE__));
	229	m_freem(m);
	230	return ENOBUFS;
	231	}
	232	n->m_len = ahlen;
	233	n->m_next = m->m_next;
	234	m->m_next = n;
	235	m->m_pkthdr.len += ahlen;
	236	ahdrpos = mtod(n, u_char *);
	237	} else {
	238	m->m_next->m_len += ahlen;
	239	m->m_next->m_data -= ahlen;
	240	m->m_pkthdr.len += ahlen;
	241	ahdrpos = mtod(m->m_next, u_char *);
	242	}
	243
	244	ip = mtod(m, struct ip ); /just to be sure*/
	245
	246	/*
	247	* initialize AH.
	248	*/
	249	if (sav->flags & SADB_X_EXT_OLD) {
	250	struct ah *ahdr;
	251
	252	ahdr = (struct ah *)ahdrpos;
	253	ahsumpos = (u_char *)(ahdr + 1);
	254	ahdr->ah_len = plen >> 2;
	255	ahdr->ah_nxt = ip->ip_p;
	256	ahdr->ah_reserve = htons(0);
	257	ahdr->ah_spi = spi;
	258	bzero(ahdr + 1, plen);
	259	} else {
260	struct newah *ahdr;
261
262	ahdr = (struct newah *)ahdrpos;
263	ahsumpos = (u_char *)(ahdr + 1);
264	ahdr->ah_len = (plen >> 2) + 1; /* plus one for seq# */
265	ahdr->ah_nxt = ip->ip_p;
266	ahdr->ah_reserve = htons(0);
267	ahdr->ah_spi = spi;
268	if (sav->replay->count == ~0) {
269	if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
270	/* XXX Is it noisy ? */
271	ipseclog((LOG_WARNING,
272	"replay counter overflowed. %s\n",
273	ipsec_logsastr(sav)));
2d21ac55	274	IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
1c79356b A	275	m_freem(m);
	276	return EINVAL;
	277	}
	278	}
2d21ac55	279	lck_mtx_lock(sadb_mutex);
1c79356b	280	sav->replay->count++;
2d21ac55	281	lck_mtx_unlock(sadb_mutex);
1c79356b A	282	/*
	283	* XXX sequence number must not be cycled, if the SA is
	284	* installed by IKE daemon.
	285	*/
	286	ahdr->ah_seq = htonl(sav->replay->count);
	287	bzero(ahdr + 1, plen);
	288	}
	289
	290	/*
	291	* modify IPv4 header.
	292	*/
	293	ip->ip_p = IPPROTO_AH;
	294	if (ahlen < (IP_MAXPACKET - ntohs(ip->ip_len)))
	295	ip->ip_len = htons(ntohs(ip->ip_len) + ahlen);
	296	else {
	297	ipseclog((LOG_ERR, "IPv4 AH output: size exceeds limit\n"));
2d21ac55	298	IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
1c79356b A	299	m_freem(m);
	300	return EMSGSIZE;
	301	}
	302
	303	/*
	304	* If there is source routing option, update destination field in
	305	* the IPv4 header to the final destination.
	306	* Note that we do not need to update source routing option itself
	307	* (as done in IPv4 AH processing -- see ip6_output()), since
	308	* source routing option is not part of the ICV computation.
	309	*/
	310	finaldst = ah4_finaldst(m);
	311	if (finaldst) {
	312	dst.s_addr = ip->ip_dst.s_addr;
	313	ip->ip_dst.s_addr = finaldst->s_addr;
	314	}
	315
	316	/*
	317	* calcurate the checksum, based on security association
	318	* and the algorithm specified.
	319	*/
9bccf70c	320	error = ah4_calccksum(m, (caddr_t)ahsumpos, plen, algo, sav);
1c79356b A	321	if (error) {
	322	ipseclog((LOG_ERR,
	323	"error after ah4_calccksum, called from ah4_output"));
9bccf70c	324	m_freem(m);
1c79356b	325	m = NULL;
2d21ac55	326	IPSEC_STAT_INCREMENT(ipsecstat.out_inval);
1c79356b A	327	return error;
	328	}
	329
	330	if (finaldst) {
	331	ip = mtod(m, struct ip ); /just to make sure*/
	332	ip->ip_dst.s_addr = dst.s_addr;
	333	}
2d21ac55	334	lck_mtx_lock(sadb_stat_mutex);
1c79356b A	335	ipsecstat.out_success++;
1c79356b A	336	ipsecstat.out_ahhist[sav->alg_auth]++;
2d21ac55	337	lck_mtx_unlock(sadb_stat_mutex);
1c79356b A	338	key_sa_recordxfer(sav, m);
	339
	340	return 0;
	341	}
9bccf70c	342	#endif
1c79356b A	343
	344	/* Calculate AH length */
	345	int
	346	ah_hdrlen(sav)
	347	struct secasvar *sav;
	348	{
9bccf70c	349	const struct ah_algorithm *algo;
1c79356b A	350	int plen, ahlen;
1c79356b A	351
9bccf70c A	352	algo = ah_algorithm_lookup(sav->alg_auth);
	353	if (!algo)
	354	return 0;
1c79356b A	355	if (sav->flags & SADB_X_EXT_OLD) {
	356	/* RFC 1826 */
	357	plen = ((algo->sumsiz)(sav) + 3) & ~(4 - 1); /XXX pad to 8byte?*/
	358	ahlen = plen + sizeof(struct ah);
	359	} else {
	360	/* RFC 2402 */
	361	plen = ((algo->sumsiz)(sav) + 3) & ~(4 - 1); /XXX pad to 8byte?*/
	362	ahlen = plen + sizeof(struct newah);
	363	}
	364
	365	return(ahlen);
	366	}
	367
	368	#if INET6
	369	/*
	370	* Fill in the Authentication Header and calculate checksum.
	371	*/
	372	int
2d21ac55	373	ah6_output(m, nexthdrp, md, sav)
1c79356b A	374	struct mbuf *m;
	375	u_char *nexthdrp;
	376	struct mbuf *md;
2d21ac55	377	struct secasvar *sav;
1c79356b A	378	{
	379	struct mbuf *mprev;
	380	struct mbuf *mah;
9bccf70c	381	const struct ah_algorithm *algo;
1c79356b A	382	u_int32_t spi;
	383	u_char *ahsumpos = NULL;
	384	size_t plen; /AH payload size in bytes/
	385	int error = 0;
	386	int ahlen;
	387	struct ip6_hdr *ip6;
	388
	389	if (m->m_len < sizeof(struct ip6_hdr)) {
	390	ipseclog((LOG_DEBUG, "ah6_output: first mbuf too short\n"));
	391	m_freem(m);
	392	return EINVAL;
	393	}
	394
	395	ahlen = ah_hdrlen(sav);
	396	if (ahlen == 0)
	397	return 0;
	398
	399	for (mprev = m; mprev && mprev->m_next != md; mprev = mprev->m_next)
	400	;
	401	if (!mprev \|\| mprev->m_next != md) {
	402	ipseclog((LOG_DEBUG, "ah6_output: md is not in chain\n"));
	403	m_freem(m);
	404	return EINVAL;
	405	}
	406
	407	MGET(mah, M_DONTWAIT, MT_DATA);
	408	if (!mah) {
	409	m_freem(m);
	410	return ENOBUFS;
	411	}
	412	if (ahlen > MLEN) {
	413	MCLGET(mah, M_DONTWAIT);
	414	if ((mah->m_flags & M_EXT) == 0) {
	415	m_free(mah);
	416	m_freem(m);
	417	return ENOBUFS;
	418	}
	419	}
	420	mah->m_len = ahlen;
	421	mah->m_next = md;
	422	mprev->m_next = mah;
	423	m->m_pkthdr.len += ahlen;
	424
	425	/* fix plen */
	426	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) > IPV6_MAXPACKET) {
	427	ipseclog((LOG_ERR,
	428	"ip6_output: AH with IPv6 jumbogram is not supported\n"));
	429	m_freem(m);
	430	return EINVAL;
	431	}
	432	ip6 = mtod(m, struct ip6_hdr *);
	433	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
	434
	435	if ((sav->flags & SADB_X_EXT_OLD) == 0 && !sav->replay) {
	436	ipseclog((LOG_DEBUG, "ah6_output: internal error: "
2d21ac55 A	437	"sav->replay is null: SPI=%u\n",
	438	(u_int32_t)ntohl(sav->spi)));
	439	IPSEC_STAT_INCREMENT(ipsec6stat.out_inval);
1c79356b A	440	m_freem(m);
	441	return EINVAL;
	442	}
	443
9bccf70c A	444	algo = ah_algorithm_lookup(sav->alg_auth);
	445	if (!algo) {
	446	ipseclog((LOG_ERR, "ah6_output: unsupported algorithm: "
	447	"SPI=%u\n", (u_int32_t)ntohl(sav->spi)));
2d21ac55	448	IPSEC_STAT_INCREMENT(ipsec6stat.out_inval);
9bccf70c A	449	m_freem(m);
	450	return EINVAL;
	451	}
1c79356b A	452	spi = sav->spi;
	453
	454	/*
	455	* initialize AH.
	456	*/
	457	if (sav->flags & SADB_X_EXT_OLD) {
	458	struct ah ahdr = mtod(mah, struct ah );
	459
	460	plen = mah->m_len - sizeof(struct ah);
	461	ahsumpos = (u_char *)(ahdr + 1);
	462	ahdr->ah_nxt = *nexthdrp;
	463	*nexthdrp = IPPROTO_AH;
	464	ahdr->ah_len = plen >> 2;
	465	ahdr->ah_reserve = htons(0);
	466	ahdr->ah_spi = spi;
	467	bzero(ahdr + 1, plen);
	468	} else {
	469	struct newah ahdr = mtod(mah, struct newah );
	470
	471	plen = mah->m_len - sizeof(struct newah);
	472	ahsumpos = (u_char *)(ahdr + 1);
	473	ahdr->ah_nxt = *nexthdrp;
	474	*nexthdrp = IPPROTO_AH;
	475	ahdr->ah_len = (plen >> 2) + 1; /* plus one for seq# */
	476	ahdr->ah_reserve = htons(0);
	477	ahdr->ah_spi = spi;
	478	if (sav->replay->count == ~0) {
	479	if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
	480	/* XXX Is it noisy ? */
	481	ipseclog((LOG_WARNING,
2d21ac55	482	"replay counter overflowed. %s\n",
1c79356b	483	ipsec_logsastr(sav)));
2d21ac55	484	IPSEC_STAT_INCREMENT(ipsec6stat.out_inval);
1c79356b A	485	m_freem(m);
	486	return EINVAL;
	487	}
	488	}
2d21ac55	489	lck_mtx_lock(sadb_mutex);
1c79356b	490	sav->replay->count++;
2d21ac55	491	lck_mtx_unlock(sadb_mutex);
1c79356b A	492	/*
	493	* XXX sequence number must not be cycled, if the SA is
	494	* installed by IKE daemon.
	495	*/
	496	ahdr->ah_seq = htonl(sav->replay->count);
	497	bzero(ahdr + 1, plen);
	498	}
	499
	500	/*
	501	* calcurate the checksum, based on security association
	502	* and the algorithm specified.
	503	*/
9bccf70c	504	error = ah6_calccksum(m, (caddr_t)ahsumpos, plen, algo, sav);
1c79356b	505	if (error) {
2d21ac55	506	IPSEC_STAT_INCREMENT(ipsec6stat.out_inval);
1c79356b A	507	m_freem(m);
1c79356b A	508	} else {
2d21ac55	509	IPSEC_STAT_INCREMENT(ipsec6stat.out_success);
1c79356b A	510	key_sa_recordxfer(sav, m);
1c79356b A	511	}
2d21ac55	512	IPSEC_STAT_INCREMENT(ipsec6stat.out_ahhist[sav->alg_auth]);
1c79356b A	513
	514	return(error);
	515	}
	516	#endif
	517
9bccf70c	518	#if INET
1c79356b A	519	/*
	520	* Find the final destination if there is loose/strict source routing option.
	521	* Returns NULL if there's no source routing options.
	522	* Returns NULL on errors too.
	523	* Note that this function will return a pointer INTO the given parameter,
	524	* struct mbuf *m.
	525	* The mbuf must be pulled up toward, at least, ip option part.
	526	*/
	527	static struct in_addr *
	528	ah4_finaldst(m)
	529	struct mbuf *m;
	530	{
	531	struct ip *ip;
	532	int optlen;
	533	u_char *q;
	534	int i;
	535	int hlen;
	536
	537	if (!m)
	538	panic("ah4_finaldst: m == NULL");
	539	ip = mtod(m, struct ip *);
	540	#ifdef _IP_VHL
	541	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
	542	#else
	543	hlen = ip->ip_hl << 2;
	544	#endif
	545
	546	if (m->m_len < hlen) {
	547	ipseclog((LOG_DEBUG,
	548	"ah4_finaldst: parameter mbuf wrong (not pulled up)\n"));
	549	return NULL;
	550	}
	551
	552	if (hlen == sizeof(struct ip))
	553	return NULL;
	554
	555	optlen = hlen - sizeof(struct ip);
	556	if (optlen < 0) {
	557	ipseclog((LOG_DEBUG, "ah4_finaldst: wrong optlen %d\n",
	558	optlen));
	559	return NULL;
	560	}
	561
	562	q = (u_char *)(ip + 1);
	563	i = 0;
	564	while (i < optlen) {
9bccf70c A	565	if (i + IPOPT_OPTVAL >= optlen)
	566	return NULL;
	567	if (q[i + IPOPT_OPTVAL] == IPOPT_EOL \|\|
	568	q[i + IPOPT_OPTVAL] == IPOPT_NOP \|\|
	569	i + IPOPT_OLEN < optlen)
	570	;
	571	else
	572	return NULL;
	573
1c79356b A	574	switch (q[i + IPOPT_OPTVAL]) {
	575	case IPOPT_EOL:
	576	i = optlen; /* bye */
	577	break;
	578	case IPOPT_NOP:
	579	i++;
	580	break;
	581	case IPOPT_LSRR:
	582	case IPOPT_SSRR:
9bccf70c A	583	if (q[i + IPOPT_OLEN] < 2 + sizeof(struct in_addr) \|\|
9bccf70c A	584	optlen - i < q[i + IPOPT_OLEN]) {
1c79356b A	585	ipseclog((LOG_ERR,
	586	"ip_finaldst: invalid IP option "
	587	"(code=%02x len=%02x)\n",
	588	q[i + IPOPT_OPTVAL], q[i + IPOPT_OLEN]));
	589	return NULL;
	590	}
	591	i += q[i + IPOPT_OLEN] - sizeof(struct in_addr);
	592	return (struct in_addr *)(q + i);
	593	default:
9bccf70c A	594	if (q[i + IPOPT_OLEN] < 2 \|\|
9bccf70c A	595	optlen - i < q[i + IPOPT_OLEN]) {
1c79356b A	596	ipseclog((LOG_ERR,
	597	"ip_finaldst: invalid IP option "
	598	"(code=%02x len=%02x)\n",
	599	q[i + IPOPT_OPTVAL], q[i + IPOPT_OLEN]));
	600	return NULL;
	601	}
	602	i += q[i + IPOPT_OLEN];
	603	break;
	604	}
	605	}
	606	return NULL;
	607	}
9bccf70c	608	#endif