pfkey.c

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//==========================================================================
//
//      src/pfkey.c
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD, 
// FreeBSD or other sources, and are covered by the appropriate
// copyright disclaimers included herein.
//
// Portions created by Red Hat are
// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================

/*	$KAME: pfkey.c,v 1.47 2003/10/02 19:52:12 itojun Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 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.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <net/pfkeyv2.h>
#include <netkey/key_var.h>
#include <netinet/in.h>
#include <netinet6/ipsec.h>

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>

#include "ipsec_strerror.h"
#include "libpfkey.h"

#define CALLOC(size, cast) (cast)calloc(1, (size))

static int findsupportedmap __P((int));
static int setsupportedmap __P((struct sadb_supported *));
static struct sadb_alg *findsupportedalg __P((u_int, u_int));
static int pfkey_send_x1 __P((int, u_int, u_int, u_int, struct sockaddr *,
	struct sockaddr *, u_int32_t, u_int32_t, u_int, caddr_t,
	u_int, u_int, u_int, u_int, u_int, u_int32_t, u_int32_t,
	u_int32_t, u_int32_t, u_int32_t));
static int pfkey_send_x2 __P((int, u_int, u_int, u_int,
	struct sockaddr *, struct sockaddr *, u_int32_t));
static int pfkey_send_x3 __P((int, u_int, u_int));
static int pfkey_send_x4 __P((int, u_int, struct sockaddr *, u_int,
	struct sockaddr *, u_int, u_int, u_int64_t, u_int64_t,
	char *, int, u_int32_t));
static int pfkey_send_x5 __P((int, u_int, u_int32_t));

static caddr_t pfkey_setsadbmsg __P((caddr_t, caddr_t, u_int, u_int,
	u_int, u_int32_t, pid_t));
static caddr_t pfkey_setsadbsa __P((caddr_t, caddr_t, u_int32_t, u_int,
	u_int, u_int, u_int32_t));
static caddr_t pfkey_setsadbaddr __P((caddr_t, caddr_t, u_int,
	struct sockaddr *, u_int, u_int));
static caddr_t pfkey_setsadbkey __P((caddr_t, caddr_t, u_int, caddr_t, u_int));
static caddr_t pfkey_setsadblifetime __P((caddr_t, caddr_t, u_int, u_int32_t,
	u_int32_t, u_int32_t, u_int32_t));
static caddr_t pfkey_setsadbxsa2 __P((caddr_t, caddr_t, u_int32_t, u_int32_t));

/*
 * make and search supported algorithm structure.
 */
static struct sadb_supported *ipsec_supported[] = { NULL, NULL, NULL, };

static int supported_map[] = {
	SADB_SATYPE_AH,
	SADB_SATYPE_ESP,
	SADB_X_SATYPE_IPCOMP,
};

static int
findsupportedmap(satype)
	int satype;
{
	int i;

	for (i = 0; i < sizeof(supported_map)/sizeof(supported_map[0]); i++)
		if (supported_map[i] == satype)
			return i;
	return -1;
}

static struct sadb_alg *
findsupportedalg(satype, alg_id)
	u_int satype, alg_id;
{
	int algno;
	int tlen;
	caddr_t p;

	/* validity check */
	algno = findsupportedmap(satype);
	if (algno == -1) {
		__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
		return NULL;
	}
	if (ipsec_supported[algno] == NULL) {
		__ipsec_errcode = EIPSEC_DO_GET_SUPP_LIST;
		return NULL;
	}

	tlen = ipsec_supported[algno]->sadb_supported_len
		- sizeof(struct sadb_supported);
	p = (caddr_t)(ipsec_supported[algno] + 1);
	while (tlen > 0) {
		if (tlen < sizeof(struct sadb_alg)) {
			/* invalid format */
			break;
		}
		if (((struct sadb_alg *)p)->sadb_alg_id == alg_id)
			return (struct sadb_alg *)p;

		tlen -= sizeof(struct sadb_alg);
		p += sizeof(struct sadb_alg);
	}

	__ipsec_errcode = EIPSEC_NOT_SUPPORTED;
	return NULL;
}

static int
setsupportedmap(sup)
	struct sadb_supported *sup;
{
	struct sadb_supported **ipsup;

	switch (sup->sadb_supported_exttype) {
	case SADB_EXT_SUPPORTED_AUTH:
		ipsup = &ipsec_supported[findsupportedmap(SADB_SATYPE_AH)];
		break;
	case SADB_EXT_SUPPORTED_ENCRYPT:
		ipsup = &ipsec_supported[findsupportedmap(SADB_SATYPE_ESP)];
		break;
	default:
		__ipsec_errcode = EIPSEC_INVAL_SATYPE;
		return -1;
	}

	if (*ipsup)
		free(*ipsup);

	*ipsup = malloc(sup->sadb_supported_len);
	if (!*ipsup) {
		__ipsec_set_strerror(strerror(errno));
		return -1;
	}
	memcpy(*ipsup, sup, sup->sadb_supported_len);

	return 0;
}

/*
 * check key length against algorithm specified.
 * This function is called with SADB_EXT_SUPPORTED_{AUTH,ENCRYPT} as the
 * augument, and only calls to ipsec_check_keylen2();
 * keylen is the unit of bit.
 * OUT:
 *	-1: invalid.
 *	 0: valid.
 */
int
ipsec_check_keylen(supported, alg_id, keylen)
	u_int supported;
	u_int alg_id;
	u_int keylen;
{
	int satype;

	/* validity check */
	switch (supported) {
	case SADB_EXT_SUPPORTED_AUTH:
		satype = SADB_SATYPE_AH;
		break;
	case SADB_EXT_SUPPORTED_ENCRYPT:
		satype = SADB_SATYPE_ESP;
		break;
	default:
		__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
		return -1;
	}

	return ipsec_check_keylen2(satype, alg_id, keylen);
}

/*
 * check key length against algorithm specified.
 * satype is one of satype defined at pfkeyv2.h.
 * keylen is the unit of bit.
 * OUT:
 *	-1: invalid.
 *	 0: valid.
 */
int
ipsec_check_keylen2(satype, alg_id, keylen)
	u_int satype;
	u_int alg_id;
	u_int keylen;
{
	struct sadb_alg *alg;

	alg = findsupportedalg(satype, alg_id);
	if (!alg)
		return -1;

	if (keylen < alg->sadb_alg_minbits || keylen > alg->sadb_alg_maxbits) {
		__ipsec_errcode = EIPSEC_INVAL_KEYLEN;
		return -1;
	}

	__ipsec_errcode = EIPSEC_NO_ERROR;
	return 0;
}

/*
 * get max/min key length against algorithm specified.
 * satype is one of satype defined at pfkeyv2.h.
 * keylen is the unit of bit.
 * OUT:
 *	-1: invalid.
 *	 0: valid.
 */
int
ipsec_get_keylen(supported, alg_id, alg0)
	u_int supported, alg_id;
	struct sadb_alg *alg0;
{
	struct sadb_alg *alg;
	u_int satype;

	/* validity check */
	if (!alg0) {
		__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
		return -1;
	}

	switch (supported) {
	case SADB_EXT_SUPPORTED_AUTH:
		satype = SADB_SATYPE_AH;
		break;
	case SADB_EXT_SUPPORTED_ENCRYPT:
		satype = SADB_SATYPE_ESP;
		break;
	default:
		__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
		return -1;
	}

	alg = findsupportedalg(satype, alg_id);
	if (!alg)
		return -1;

	memcpy(alg0, alg, sizeof(*alg0));

	__ipsec_errcode = EIPSEC_NO_ERROR;
	return 0;
}

/*
 * set the rate for SOFT lifetime against HARD one.
 * If rate is more than 100 or equal to zero, then set to 100.
 */
static u_int soft_lifetime_allocations_rate = PFKEY_SOFT_LIFETIME_RATE;
static u_int soft_lifetime_bytes_rate = PFKEY_SOFT_LIFETIME_RATE;
static u_int soft_lifetime_addtime_rate = PFKEY_SOFT_LIFETIME_RATE;
static u_int soft_lifetime_usetime_rate = PFKEY_SOFT_LIFETIME_RATE;

u_int
pfkey_set_softrate(type, rate)
	u_int type, rate;
{
	__ipsec_errcode = EIPSEC_NO_ERROR;

	if (rate > 100 || rate == 0)
		rate = 100;

	switch (type) {
	case SADB_X_LIFETIME_ALLOCATIONS:
		soft_lifetime_allocations_rate = rate;
		return 0;
	case SADB_X_LIFETIME_BYTES:
		soft_lifetime_bytes_rate = rate;
		return 0;
	case SADB_X_LIFETIME_ADDTIME:
		soft_lifetime_addtime_rate = rate;
		return 0;
	case SADB_X_LIFETIME_USETIME:
		soft_lifetime_usetime_rate = rate;
		return 0;
	}

	__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
	return 1;
}

/*
 * get current rate for SOFT lifetime against HARD one.
 * ATTENTION: ~0 is returned if invalid type was passed.
 */
u_int
pfkey_get_softrate(type)
	u_int type;
{
	switch (type) {
	case SADB_X_LIFETIME_ALLOCATIONS:
		return soft_lifetime_allocations_rate;
	case SADB_X_LIFETIME_BYTES:
		return soft_lifetime_bytes_rate;
	case SADB_X_LIFETIME_ADDTIME:
		return soft_lifetime_addtime_rate;
	case SADB_X_LIFETIME_USETIME:
		return soft_lifetime_usetime_rate;
	}

	return ~0;
}

/*
 * sending SADB_GETSPI message to the kernel.
 * OUT:
 *	positive: success and return length sent.
 *	-1	: error occured, and set errno.
 */
int
pfkey_send_getspi(so, satype, mode, src, dst, min, max, reqid, seq)
	int so;
	u_int satype, mode;
	struct sockaddr *src, *dst;
	u_int32_t min, max, reqid, seq;
{
	struct sadb_msg *newmsg;
	caddr_t ep;
	int len;
	int need_spirange = 0;
	caddr_t p;
	int plen;

	/* validity check */
	if (src == NULL || dst == NULL) {
		__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
		return -1;
	}
	if (src->sa_family != dst->sa_family) {
		__ipsec_errcode = EIPSEC_FAMILY_MISMATCH;
		return -1;
	}
	if (min > max || (min > 0 && min <= 255)) {
		__ipsec_errcode = EIPSEC_INVAL_SPI;
		return -1;
	}
	switch (src->sa_family) {
	case AF_INET:
		plen = sizeof(struct in_addr) << 3;
		break;
	case AF_INET6:
		plen = sizeof(struct in6_addr) << 3;
		break;
	default:
		__ipsec_errcode = EIPSEC_INVAL_FAMILY;
		return -1;
	}

	/* create new sadb_msg to send. */
	len = sizeof(struct sadb_msg)
		+ sizeof(struct sadb_x_sa2)
		+ sizeof(struct sadb_address)
		+ PFKEY_ALIGN8(src->sa_len)
		+ sizeof(struct sadb_address)
		+ PFKEY_ALIGN8(dst->sa_len);

	if (min > 255 && max < ~0) {
		need_spirange++;
		len += sizeof(struct sadb_spirange);
	}

	if ((newmsg = CALLOC(len, struct sadb_msg *)) == NULL) {
		__ipsec_set_strerror(strerror(errno));
		return -1;
	}
	ep = ((caddr_t)newmsg) + len;

	p = pfkey_setsadbmsg((caddr_t)newmsg, ep, SADB_GETSPI,
	    len, satype, seq, getpid());
	if (!p) {
		free(newmsg);
		return -1;
	}

	p = pfkey_setsadbxsa2(p, ep, mode, reqid);
	if (!p) {
		free(newmsg);
		return -1;
	}

	/* set sadb_address for source */
	p = pfkey_setsadbaddr(p, ep, SADB_EXT_ADDRESS_SRC, src, plen,
	    IPSEC_ULPROTO_ANY);
	if (!p) {
		free(newmsg);
		return -1;
	}

	/* set sadb_address for destination */
	p = pfkey_setsadbaddr(p, ep, SADB_EXT_ADDRESS_DST, dst, plen,
	    IPSEC_ULPROTO_ANY);
	if (!p) {
		free(newmsg);
		return -1;
	}

	/* proccessing spi range */
	if (need_spirange) {
		struct sadb_spirange spirange;

		if (p + sizeof(spirange) > ep) {
			free(newmsg);
			return -1;
		}

		memset(&spirange, 0, sizeof(spirange));
		spirange.sadb_spirange_len = PFKEY_UNIT64(sizeof(spirange));
		spirange.sadb_spirange_exttype = SADB_EXT_SPIRANGE;
		spirange.sadb_spirange_min = min;
		spirange.sadb_spirange_max = max;

		memcpy(p, &spirange, sizeof(spirange));

		p += sizeof(spirange);
	}
	if (p != ep) {
		free(newmsg);
		return -1;
	}

	/* send message */
	len = pfkey_send(so, newmsg, len);
	free(newmsg);

	if (len < 0)
		return -1;

	__ipsec_errcode = EIPSEC_NO_ERROR;
	return len;
}

/*
 * sending SADB_UPDATE message to the kernel.
 * The length of key material is a_keylen + e_keylen.
 * OUT:
 *	positive: success and return length sent.
 *	-1	: error occured, and set errno.
 */
int
pfkey_send_update(so, satype, mode, src, dst, spi, reqid, wsize,
		keymat, e_type, e_keylen, a_type, a_keylen, flags,
		l_alloc, l_bytes, l_addtime, l_usetime, seq)
	int so;
	u_int satype, mode, wsize;
	struct sockaddr *src, *dst;
	u_int32_t spi, reqid;
	caddr_t keymat;
	u_int e_type, e_keylen, a_type, a_keylen, flags;
	u_int32_t l_alloc;
	u_int64_t l_bytes, l_addtime, l_usetime;
	u_int32_t seq;
{
	int len;
	if ((len = pfkey_send_x1(so, SADB_UPDATE, satype, mode, src, dst, spi,
			reqid, wsize,
			keymat, e_type, e_keylen, a_type, a_keylen, flags,
			l_alloc, l_bytes, l_addtime, l_usetime, seq)) < 0)
		return -1;

	return len;
}

/*
 * sending SADB_ADD message to the kernel.
 * The length of key material is a_keylen + e_keylen.
 * OUT:
 *	positive: success and return length sent.
 *	-1	: error occured, and set errno.
 */
int
pfkey_send_add(so, satype, mode, src, dst, spi, reqid, wsize,
		keymat, e_type, e_keylen, a_type, a_keylen, flags,
		l_alloc, l_bytes, l_addtime, l_usetime, seq)
	int so;
	u_int satype, mode, wsize;
	struct sockaddr *src, *dst;
	u_int32_t spi, reqid;
	caddr_t keymat;
	u_int e_type, e_keylen, a_type, a_keylen, flags;
	u_int32_t l_alloc;
	u_int64_t l_bytes, l_addtime, l_usetime;
	u_int32_t seq;
{
	int len;
	if ((len = pfkey_send_x1(so, SADB_ADD, satype, mode, src, dst, spi,
			reqid, wsize,
			keymat, e_type, e_keylen, a_type, a_keylen, flags,
			l_alloc, l_bytes, l_addtime, l_usetime, seq)) < 0)
		return -1;

	return len;
}

/*
 * sending SADB_DELETE message to the kernel.
 * OUT:
 *	positive: success and return length sent.
 *	-1	: error occured, and set errno.
 */
int
pfkey_send_delete(so, satype, mode, src, dst, spi)
	int so;
	u_int satype, mode;
	struct sockaddr *src, *dst;
	u_int32_t spi;
{
	int len;
	if ((len = pfkey_send_x2(so, SADB_DELETE, satype, mode, src, dst, spi)) < 0)
		return -1;

	return len;
}

/*
 * sending SADB_DELETE without spi to the kernel.  This is
 * the "delete all" request (an extension also present in
 * Solaris).
 *
 * OUT:
 *	positive: success and return length sent
 *	-1	: error occured, and set errno
 */
int
pfkey_send_delete_all(so, satype, mode, src, dst)
	int so;
	u_int satype, mode;
	struct sockaddr *src, *dst;
{
	struct sadb_msg *newmsg;
	int len;
	caddr_t p;
	int plen;
	caddr_t ep;

	/* validity check */
	if (src == NULL || dst == NULL) {
		__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
		return -1;
	}
	if (src->sa_family != dst->sa_family) {
		__ipsec_errcode = EIPSEC_FAMILY_MISMATCH;
		return -1;
	}
	switch (src->sa_family) {
	case AF_INET:
		plen = sizeof(struct in_addr) << 3;
		break;
	case AF_INET6:
		plen = sizeof(struct in6_addr) << 3;
		break;
	default:
		__ipsec_errcode = EIPSEC_INVAL_FAMILY;
		return -1;
	}

	/* create new sadb_msg to reply. */
	len = sizeof(struct sadb_msg)
		+ sizeof(struct sadb_address)
		+ PFKEY_ALIGN8(src->sa_len)
		+ sizeof(struct sadb_address)
		+ PFKEY_ALIGN8(dst->sa_len);

	if ((newmsg = CALLOC(len, struct sadb_msg *)) == NULL) {
		__ipsec_set_strerror(strerror(errno));
		return -1;
	}
	ep = ((caddr_t)newmsg) + len;

	p = pfkey_setsadbmsg((caddr_t)newmsg, ep, SADB_DELETE, len, satype, 0,
	    getpid());
	if (!p) {
		free(newmsg);
		return -1;
	}
	p = pfkey_setsadbaddr(p, ep, SADB_EXT_ADDRESS_SRC, src, plen,
	    IPSEC_ULPROTO_ANY);
	if (!p) {
		free(newmsg);
		return -1;
	}
	p = pfkey_setsadbaddr(p, ep, SADB_EXT_ADDRESS_DST, dst, plen,
	    IPSEC_ULPROTO_ANY);
	if (!p || p != ep) {
		free(newmsg);
		return -1;
	}

	/* send message */
	len = pfkey_send(so, newmsg, len);
	free(newmsg);

	if (len < 0)
		return -1;

	__ipsec_errcode = EIPSEC_NO_ERROR;
	return len;
}

/*
 * sending SADB_GET message to the kernel.
 * OUT:
 *	positive: success and return length sent.
 *	-1	: error occured, and set errno.
 */
int
pfkey_send_get(so, satype, mode, src, dst, spi)
	int so;
	u_int satype, mode;
	struct sockaddr *src, *dst;
	u_int32_t spi;
{
	int len;
	if ((len = pfkey_send_x2(so, SADB_GET, satype, mode, src, dst, spi)) < 0)
		return -1;

	return len;
}

/*
 * sending SADB_REGISTER message to the kernel.
 * OUT:
 *	positive: success and return length sent.
 *	-1	: error occured, and set errno.
 */
int
pfkey_send_register(so, satype)
	int so;
	u_int satype;
{
	int len, algno;

	if (satype == PF_UNSPEC) {
		for (algno = 0;
		     algno < sizeof(supported_map)/sizeof(supported_map[0]);
		     algno++) {
			if (ipsec_supported[algno]) {
				free(ipsec_supported[algno]);
				ipsec_supported[algno] = NULL;
			}
		}
	} else {
		algno = findsupportedmap(satype);
		if (algno == -1) {
			__ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
			return -1;
		}

		if (ipsec_supported[algno]) {
			free(ipsec_supported[algno]);
			ipsec_supported[algno] = NULL;
		}
	}

	if ((len = pfkey_send_x3(so, SADB_REGISTER, satype)) < 0)
		return -1;

	return len;
}

/*
 * receiving SADB_REGISTER message from the kernel, and copy buffer for