/*      $KAME: pfkey.c,v 1.46 2003/08/26 03:37:06 itojun Exp $  */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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 <netipsec/key_var.h>
#include <netinet/in.h>
#include <netipsec/ipsec.h>

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

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

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

static int findsupportedmap(int);
static int setsupportedmap(struct sadb_supported *);
static struct sadb_alg *findsupportedalg(u_int, u_int);
static int pfkey_send_x1(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(int, u_int, u_int, u_int,
        struct sockaddr *, struct sockaddr *, u_int32_t);
static int pfkey_send_x3(int, u_int, u_int);
static int pfkey_send_x4(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(int, u_int, u_int32_t);

static caddr_t pfkey_setsadbmsg(caddr_t, caddr_t, u_int, u_int,
        u_int, u_int32_t, pid_t);
static caddr_t pfkey_setsadbsa(caddr_t, caddr_t, u_int32_t, u_int,
        u_int, u_int, u_int32_t);
static caddr_t pfkey_setsadbxreplay(caddr_t, caddr_t, uint32_t);
static caddr_t pfkey_setsadbaddr(caddr_t, caddr_t, u_int,
        struct sockaddr *, u_int, u_int);
static caddr_t pfkey_setsadbkey(caddr_t, caddr_t, u_int, caddr_t, u_int);
static caddr_t pfkey_setsadblifetime(caddr_t, caddr_t, u_int, u_int32_t,
        u_int32_t, u_int32_t, u_int32_t);
static caddr_t pfkey_setsadbxsa2(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, NULL };

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

static int
findsupportedmap(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(u_int satype, u_int 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(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(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(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(u_int supported, u_int 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(u_int type, u_int 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(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 occurred, and set errno.
 */
int
pfkey_send_getspi(int so, u_int satype, u_int mode, struct sockaddr *src,
    struct sockaddr *dst, u_int32_t min, uint32_t max, uint32_t reqid,
    uint32_t 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;
        }

        /* processing 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 occurred, and set errno.
 */
int
pfkey_send_update(int so, u_int satype, u_int mode, struct sockaddr *src,
    struct sockaddr *dst, u_int32_t spi, u_int32_t reqid, u_int wsize,
    caddr_t keymat, u_int e_type, u_int e_keylen, u_int a_type, u_int a_keylen,
    u_int flags, u_int32_t l_alloc, u_int64_t l_bytes, u_int64_t l_addtime,
    u_int64_t 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 occurred, and set errno.
 */
int
pfkey_send_add(int so, u_int satype, u_int mode, struct sockaddr *src,
    struct sockaddr *dst, u_int32_t spi, u_int32_t reqid, u_int wsize,
    caddr_t keymat, u_int e_type, u_int e_keylen, u_int a_type, u_int a_keylen,
    u_int flags, u_int32_t l_alloc, u_int64_t l_bytes, u_int64_t l_addtime,
    u_int64_t 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 occurred, and set errno.
 */
int
pfkey_send_delete(int so, u_int satype, u_int mode, struct sockaddr *src,
    struct sockaddr *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 occurred, and set errno
 */
int
pfkey_send_delete_all(int so, u_int satype, u_int mode, struct sockaddr *src,
    struct sockaddr *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 occurred, and set errno.
 */
int
pfkey_send_get(int so, u_int satype, u_int mode, struct sockaddr *src,
    struct sockaddr *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 occurred, and set errno.
 */
int
pfkey_send_register(int so, u_int satype)
{
        int len, algno;

        if (satype == SADB_SATYPE_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
 * sadb_supported returned into ipsec_supported.
 * OUT:
 *       0: success and return length sent.
 *      -1: error occurred, and set errno.
 */
int
pfkey_recv_register(int so)
{
        pid_t pid = getpid();
        struct sadb_msg *newmsg;
        int error = -1;

        /* receive message */
        for (;;) {
                if ((newmsg = pfkey_recv(so)) == NULL)
                        return -1;
                if (newmsg->sadb_msg_type == SADB_REGISTER &&
                    newmsg->sadb_msg_pid == pid)
                        break;
                free(newmsg);
        }

        /* check and fix */
        newmsg->sadb_msg_len = PFKEY_UNUNIT64(newmsg->sadb_msg_len);

        error = pfkey_set_supported(newmsg, newmsg->sadb_msg_len);
        free(newmsg);

        if (error == 0)
                __ipsec_errcode = EIPSEC_NO_ERROR;

        return error;
}

/*
 * receiving SADB_REGISTER message from the kernel, and copy buffer for
 * sadb_supported returned into ipsec_supported.
 * NOTE: sadb_msg_len must be host order.
 * IN:
 *      tlen: msg length, it's to makeing sure.
 * OUT:
 *       0: success and return length sent.
 *      -1: error occurred, and set errno.
 */
int
pfkey_set_supported(struct sadb_msg *msg, int tlen)
{
        struct sadb_supported *sup;
        caddr_t p;
        caddr_t ep;

        /* validity */
        if (msg->sadb_msg_len != tlen) {
                __ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
                return -1;
        }

        p = (caddr_t)msg;
        ep = p + tlen;

        p += sizeof(struct sadb_msg);

        while (p < ep) {
                sup = (struct sadb_supported *)p;
                if (ep < p + sizeof(*sup) ||
                    PFKEY_EXTLEN(sup) < sizeof(*sup) ||
                    ep < p + sup->sadb_supported_len) {
                        /* invalid format */
                        break;
                }

                switch (sup->sadb_supported_exttype) {
                case SADB_EXT_SUPPORTED_AUTH:
                case SADB_EXT_SUPPORTED_ENCRYPT:
                        break;
                default:
                        __ipsec_errcode = EIPSEC_INVAL_SATYPE;
                        return -1;
                }

                /* fixed length */
                sup->sadb_supported_len = PFKEY_EXTLEN(sup);

                /* set supported map */
                if (setsupportedmap(sup) != 0)
                        return -1;

                p += sup->sadb_supported_len;
        }

        if (p != ep) {
                __ipsec_errcode = EIPSEC_INVAL_SATYPE;
                return -1;
        }

        __ipsec_errcode = EIPSEC_NO_ERROR;

        return 0;
}

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

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

        return len;
}

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

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

        return len;
}

/*
 * sending SADB_X_PROMISC message to the kernel.
 * NOTE that this function handles promisc mode toggle only.
 * IN:
 *      flag:   set promisc off if zero, set promisc on if non-zero.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 *      0     : error occurred, and set errno.
 *      others: a pointer to new allocated buffer in which supported
 *              algorithms is.
 */
int
pfkey_send_promisc_toggle(int so, int flag)
{
        int len;

        if ((len = pfkey_send_x3(so, SADB_X_PROMISC, (flag ? 1 : 0))) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_X_SPDADD message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spdadd(int so, struct sockaddr *src, u_int prefs,
    struct sockaddr *dst, u_int prefd, u_int proto, caddr_t policy,
    int policylen, u_int32_t seq)
{
        int len;

        if ((len = pfkey_send_x4(so, SADB_X_SPDADD,
                                src, prefs, dst, prefd, proto,
                                0, 0,
                                policy, policylen, seq)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_X_SPDADD message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spdadd2(int so, struct sockaddr *src, u_int prefs,
    struct sockaddr *dst, u_int prefd, u_int proto, u_int64_t ltime,
    u_int64_t vtime, caddr_t policy, int policylen, u_int32_t seq)
{
        int len;

        if ((len = pfkey_send_x4(so, SADB_X_SPDADD,
                                src, prefs, dst, prefd, proto,
                                ltime, vtime,
                                policy, policylen, seq)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_X_SPDUPDATE message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spdupdate(int so, struct sockaddr *src, u_int prefs,
    struct sockaddr *dst, u_int prefd, u_int proto, caddr_t policy,
    int policylen, u_int32_t seq)
{
        int len;

        if ((len = pfkey_send_x4(so, SADB_X_SPDUPDATE,
                                src, prefs, dst, prefd, proto,
                                0, 0,
                                policy, policylen, seq)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_X_SPDUPDATE message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spdupdate2(int so, struct sockaddr *src, u_int prefs,
    struct sockaddr *dst, u_int prefd, u_int proto, u_int64_t ltime,
    u_int64_t vtime, caddr_t policy, int policylen, u_int32_t seq)
{
        int len;

        if ((len = pfkey_send_x4(so, SADB_X_SPDUPDATE,
                                src, prefs, dst, prefd, proto,
                                ltime, vtime,
                                policy, policylen, seq)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_X_SPDDELETE message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spddelete(int so, struct sockaddr *src, u_int prefs,
    struct sockaddr *dst, u_int prefd, u_int proto, caddr_t policy,
    int policylen, u_int32_t seq)
{
        int len;

        if (policylen != sizeof(struct sadb_x_policy)) {
                __ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
                return -1;
        }

        if ((len = pfkey_send_x4(so, SADB_X_SPDDELETE,
                                src, prefs, dst, prefd, proto,
                                0, 0,
                                policy, policylen, seq)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_X_SPDDELETE message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spddelete2(int so, u_int32_t spid)
{
        int len;

        if ((len = pfkey_send_x5(so, SADB_X_SPDDELETE2, spid)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_X_SPDGET message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spdget(int so, u_int32_t spid)
{
        int len;

        if ((len = pfkey_send_x5(so, SADB_X_SPDGET, spid)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_X_SPDSETIDX message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spdsetidx(int so, struct sockaddr *src, u_int prefs,
    struct sockaddr *dst, u_int prefd, u_int proto, caddr_t policy,
    int policylen, u_int32_t seq)
{
        int len;

        if (policylen != sizeof(struct sadb_x_policy)) {
                __ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
                return -1;
        }

        if ((len = pfkey_send_x4(so, SADB_X_SPDSETIDX,
                                src, prefs, dst, prefd, proto,
                                0, 0,
                                policy, policylen, seq)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_SPDFLUSH message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spdflush(int so)
{
        int len;

        if ((len = pfkey_send_x3(so, SADB_X_SPDFLUSH, SADB_SATYPE_UNSPEC)) < 0)
                return -1;

        return len;
}

/*
 * sending SADB_SPDDUMP message to the kernel.
 * OUT:
 *      positive: success and return length sent.
 *      -1      : error occurred, and set errno.
 */
int
pfkey_send_spddump(int so)
{
        int len;

        if ((len = pfkey_send_x3(so, SADB_X_SPDDUMP, SADB_SATYPE_UNSPEC)) < 0)
                return -1;

        return len;
}

/* sending SADB_ADD or SADB_UPDATE message to the kernel */
static int
pfkey_send_x1(int so, u_int type, u_int satype, u_int mode,
    struct sockaddr *src, struct sockaddr *dst, u_int32_t spi, u_int32_t reqid,
    u_int wsize, caddr_t keymat, u_int e_type, u_int e_keylen, u_int a_type,
    u_int a_keylen, u_int flags, u_int32_t l_alloc, u_int32_t l_bytes,
    u_int32_t l_addtime, u_int32_t l_usetime, u_int32_t seq)
{
        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;
        }

        switch (satype) {
        case SADB_SATYPE_ESP:
                if (e_type == SADB_EALG_NONE) {
                        __ipsec_errcode = EIPSEC_NO_ALGS;
                        return -1;
                }
                break;
        case SADB_SATYPE_AH:
                if (e_type != SADB_EALG_NONE) {
                        __ipsec_errcode = EIPSEC_INVAL_ALGS;
                        return -1;
                }
                if (a_type == SADB_AALG_NONE) {
                        __ipsec_errcode = EIPSEC_NO_ALGS;
                        return -1;
                }
                break;
        case SADB_X_SATYPE_IPCOMP:
                if (e_type == SADB_X_CALG_NONE) {
                        __ipsec_errcode = EIPSEC_INVAL_ALGS;
                        return -1;
                }
                if (a_type != SADB_AALG_NONE) {
                        __ipsec_errcode = EIPSEC_NO_ALGS;
                        return -1;
                }
                break;
        case SADB_X_SATYPE_TCPSIGNATURE:
                if (e_type != SADB_EALG_NONE) {
                        __ipsec_errcode = EIPSEC_INVAL_ALGS;
                        return -1;
                }
                if (a_type != SADB_X_AALG_TCP_MD5) {
                        __ipsec_errcode = EIPSEC_INVAL_ALGS;
                        return -1;
                }
                break;
        default:
                __ipsec_errcode = EIPSEC_INVAL_SATYPE;
                return -1;
        }

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

        if (wsize > UINT8_MAX) {
                if (wsize > (UINT32_MAX - 32) >> 3) {
                        __ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
                        return (-1);
                }
                len += sizeof(struct sadb_x_sa_replay);
        }
        if (e_type != SADB_EALG_NONE)
                len += (sizeof(struct sadb_key) + PFKEY_ALIGN8(e_keylen));
        if (a_type != SADB_AALG_NONE)
                len += (sizeof(struct sadb_key) + PFKEY_ALIGN8(a_keylen));

        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, type, len,
                             satype, seq, getpid());
        if (!p) {
                free(newmsg);
                return -1;
        }
        p = pfkey_setsadbsa(p, ep, spi, wsize, a_type, e_type, flags);
        if (!p) {
                free(newmsg);
                return -1;
        }
        p = pfkey_setsadbxsa2(p, ep, mode, reqid);
        if (!p) {
                free(newmsg);
                return -1;
        }
        if (wsize > UINT8_MAX) {
                p = pfkey_setsadbxreplay(p, ep, wsize);
                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) {
                free(newmsg);
                return -1;
        }

        if (e_type != SADB_EALG_NONE) {
                p = pfkey_setsadbkey(p, ep, SADB_EXT_KEY_ENCRYPT,
                                   keymat, e_keylen);
                if (!p) {
                        free(newmsg);
                        return -1;
                }
        }
        if (a_type != SADB_AALG_NONE) {
                p = pfkey_setsadbkey(p, ep, SADB_EXT_KEY_AUTH,
                                   keymat + e_keylen, a_keylen);
                if (!p) {
                        free(newmsg);
                        return -1;
                }
        }

        /* set sadb_lifetime for destination */
        p = pfkey_setsadblifetime(p, ep, SADB_EXT_LIFETIME_HARD,
                        l_alloc, l_bytes, l_addtime, l_usetime);
        if (!p) {
                free(newmsg);
                return -1;
        }
        p = pfkey_setsadblifetime(p, ep, SADB_EXT_LIFETIME_SOFT,
                        l_alloc, l_bytes, l_addtime, l_usetime);
        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_DELETE or SADB_GET message to the kernel */
static int
pfkey_send_x2(int so, u_int type, u_int satype, u_int mode,
    struct sockaddr *src, struct sockaddr *dst, u_int32_t spi)
{
        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_sa)
                + 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, type, len, satype, 0,
            getpid());
        if (!p) {
                free(newmsg);
                return -1;
        }
        p = pfkey_setsadbsa(p, ep, spi, 0, 0, 0, 0);
        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_REGISTER, SADB_FLUSH, SADB_DUMP or SADB_X_PROMISC message
 * to the kernel
 */
static int
pfkey_send_x3(int so, u_int type, u_int satype)
{
        struct sadb_msg *newmsg;
        int len;
        caddr_t p;
        caddr_t ep;

        /* validity check */
        switch (type) {
        case SADB_X_PROMISC:
                if (satype != 0 && satype != 1) {
                        __ipsec_errcode = EIPSEC_INVAL_SATYPE;
                        return -1;
                }
                break;
        default:
                switch (satype) {
                case SADB_SATYPE_UNSPEC:
                case SADB_SATYPE_AH:
                case SADB_SATYPE_ESP:
                case SADB_X_SATYPE_IPCOMP:
                case SADB_X_SATYPE_TCPSIGNATURE:
                        break;
                default:
                        __ipsec_errcode = EIPSEC_INVAL_SATYPE;
                        return -1;
                }
        }

        /* create new sadb_msg to send. */
        len = sizeof(struct sadb_msg);

        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, type, len, satype, 0,
            getpid());
        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_X_SPDADD message to the kernel */
static int
pfkey_send_x4(int so, u_int type, struct sockaddr *src, u_int prefs,
    struct sockaddr *dst, u_int prefd, u_int proto, u_int64_t ltime,
    u_int64_t vtime, char *policy, int policylen, u_int32_t seq)
{
        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;
        }
        if (prefs > plen || prefd > plen) {
                __ipsec_errcode = EIPSEC_INVAL_PREFIXLEN;
                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(src->sa_len)
                + sizeof(struct sadb_lifetime)
                + policylen;

        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, type, len,
            SADB_SATYPE_UNSPEC, seq, getpid());
        if (!p) {
                free(newmsg);
                return -1;
        }
        p = pfkey_setsadbaddr(p, ep, SADB_EXT_ADDRESS_SRC, src, prefs, proto);
        if (!p) {
                free(newmsg);
                return -1;
        }
        p = pfkey_setsadbaddr(p, ep, SADB_EXT_ADDRESS_DST, dst, prefd, proto);
        if (!p) {
                free(newmsg);
                return -1;
        }
        p = pfkey_setsadblifetime(p, ep, SADB_EXT_LIFETIME_HARD,
                        0, 0, ltime, vtime);
        if (!p || p + policylen != ep) {
                free(newmsg);
                return -1;
        }
        memcpy(p, policy, policylen);

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

        if (len < 0)
                return -1;

        __ipsec_errcode = EIPSEC_NO_ERROR;
        return len;
}

/* sending SADB_X_SPDGET or SADB_X_SPDDELETE message to the kernel */
static int
pfkey_send_x5(int so, u_int type, u_int32_t spid)
{
        struct sadb_msg *newmsg;
        struct sadb_x_policy xpl;
        int len;
        caddr_t p;
        caddr_t ep;

        /* create new sadb_msg to reply. */
        len = sizeof(struct sadb_msg)
                + sizeof(xpl);

        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, type, len,
            SADB_SATYPE_UNSPEC, 0, getpid());
        if (!p) {
                free(newmsg);
                return -1;
        }

        if (p + sizeof(xpl) != ep) {
                free(newmsg);
                return -1;
        }
        memset(&xpl, 0, sizeof(xpl));
        xpl.sadb_x_policy_len = PFKEY_UNIT64(sizeof(xpl));
        xpl.sadb_x_policy_exttype = SADB_X_EXT_POLICY;
        xpl.sadb_x_policy_id = spid;
        memcpy(p, &xpl, sizeof(xpl));

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

        if (len < 0)
                return -1;

        __ipsec_errcode = EIPSEC_NO_ERROR;
        return len;
}

/*
 * open a socket.
 * OUT:
 *      -1: fail.
 *      others : success and return value of socket.
 */
int
pfkey_open(void)
{
        int so;
        int bufsiz_current, bufsiz_wanted;
        int ret;
        socklen_t len;

        if ((so = socket(PF_KEY, SOCK_RAW, PF_KEY_V2)) < 0) {
                __ipsec_set_strerror(strerror(errno));
                return -1;
        }

        /*
         * This is a temporary workaround for KAME PR 154.
         * Don't really care even if it fails.
         */
        /* Try to have 128k. If we have more, do not lower it. */
        bufsiz_wanted = 128 * 1024;
        len = sizeof(bufsiz_current);
        ret = getsockopt(so, SOL_SOCKET, SO_SNDBUF,
                &bufsiz_current, &len);
        if ((ret < 0) || (bufsiz_current < bufsiz_wanted))
                (void)setsockopt(so, SOL_SOCKET, SO_SNDBUF,
                        &bufsiz_wanted, sizeof(bufsiz_wanted));

        /* Try to have have at least 2MB. If we have more, do not lower it. */
        bufsiz_wanted = 2 * 1024 * 1024;
        len = sizeof(bufsiz_current);
        ret = getsockopt(so, SOL_SOCKET, SO_RCVBUF,
                &bufsiz_current, &len);
        if (ret < 0)
                bufsiz_current = 128 * 1024;

        for (; bufsiz_wanted > bufsiz_current; bufsiz_wanted /= 2) {
                if (setsockopt(so, SOL_SOCKET, SO_RCVBUF,
                                &bufsiz_wanted, sizeof(bufsiz_wanted)) == 0)
                        break;
        }

        __ipsec_errcode = EIPSEC_NO_ERROR;
        return so;
}

/*
 * close a socket.
 * OUT:
 *       0: success.
 *      -1: fail.
 */
void
pfkey_close(int so)
{
        (void)close(so);

        __ipsec_errcode = EIPSEC_NO_ERROR;
        return;
}

/*
 * receive sadb_msg data, and return pointer to new buffer allocated.
 * Must free this buffer later.
 * OUT:
 *      NULL    : error occurred.
 *      others  : a pointer to sadb_msg structure.
 *
 * XXX should be rewritten to pass length explicitly
 */
struct sadb_msg *
pfkey_recv(int so)
{
        struct sadb_msg buf, *newmsg;
        int len, reallen;

        while ((len = recv(so, (caddr_t)&buf, sizeof(buf), MSG_PEEK)) < 0) {
                if (errno == EINTR)
                        continue;
                __ipsec_set_strerror(strerror(errno));
                return NULL;
        }

        if (len < sizeof(buf)) {
                recv(so, (caddr_t)&buf, sizeof(buf), 0);
                __ipsec_errcode = EIPSEC_MAX;
                return NULL;
        }

        /* read real message */
        reallen = PFKEY_UNUNIT64(buf.sadb_msg_len);
        if ((newmsg = CALLOC(reallen, struct sadb_msg *)) == NULL) {
                __ipsec_set_strerror(strerror(errno));
                return NULL;
        }

        while ((len = recv(so, (caddr_t)newmsg, reallen, 0)) < 0) {
                if (errno == EINTR)
                        continue;
                __ipsec_set_strerror(strerror(errno));
                free(newmsg);
                return NULL;
        }

        if (len != reallen) {
                __ipsec_errcode = EIPSEC_SYSTEM_ERROR;
                free(newmsg);
                return NULL;
        }

        /* don't trust what the kernel says, validate! */
        if (PFKEY_UNUNIT64(newmsg->sadb_msg_len) != len) {
                __ipsec_errcode = EIPSEC_SYSTEM_ERROR;
                free(newmsg);
                return NULL;
        }

        __ipsec_errcode = EIPSEC_NO_ERROR;
        return newmsg;
}

/*
 * send message to a socket.
 * OUT:
 *       others: success and return length sent.
 *      -1     : fail.
 */
int
pfkey_send(int so, struct sadb_msg *msg, int len)
{
        if ((len = send(so, (caddr_t)msg, len, 0)) < 0) {
                __ipsec_set_strerror(strerror(errno));
                return -1;
        }

        __ipsec_errcode = EIPSEC_NO_ERROR;
        return len;
}

/*
 * %%% Utilities
 * NOTE: These functions are derived from netkey/key.c in KAME.
 */
/*
 * set the pointer to each header in this message buffer.
 * IN:  msg: pointer to message buffer.
 *      mhp: pointer to the buffer initialized like below:
 *              caddr_t mhp[SADB_EXT_MAX + 1];
 * OUT: -1: invalid.
 *       0: valid.
 *
 * XXX should be rewritten to obtain length explicitly
 */
int
pfkey_align(struct sadb_msg *msg, caddr_t *mhp)
{
        struct sadb_ext *ext;
        int i;
        caddr_t p;
        caddr_t ep;     /* XXX should be passed from upper layer */

        /* validity check */
        if (msg == NULL || mhp == NULL) {
                __ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
                return -1;
        }

        /* initialize */
        for (i = 0; i < SADB_EXT_MAX + 1; i++)
                mhp[i] = NULL;

        mhp[0] = (caddr_t)msg;

        /* initialize */
        p = (caddr_t) msg;
        ep = p + PFKEY_UNUNIT64(msg->sadb_msg_len);

        /* skip base header */
        p += sizeof(struct sadb_msg);

        while (p < ep) {
                ext = (struct sadb_ext *)p;
                if (ep < p + sizeof(*ext) || PFKEY_EXTLEN(ext) < sizeof(*ext) ||
                    ep < p + PFKEY_EXTLEN(ext)) {
                        /* invalid format */
                        break;
                }

                /* duplicate check */
                /* XXX Are there duplication either KEY_AUTH or KEY_ENCRYPT ?*/
                if (mhp[ext->sadb_ext_type] != NULL &&
                    ext->sadb_ext_type != SADB_X_EXT_IF_HW_OFFL /* XXXKIB */) {
                        __ipsec_errcode = EIPSEC_INVAL_EXTTYPE;
                        return -1;
                }

                /* set pointer */
                switch (ext->sadb_ext_type) {
                case SADB_EXT_SA:
                case SADB_EXT_LIFETIME_CURRENT:
                case SADB_EXT_LIFETIME_HARD:
                case SADB_EXT_LIFETIME_SOFT:
                case SADB_EXT_ADDRESS_SRC:
                case SADB_EXT_ADDRESS_DST:
                case SADB_EXT_ADDRESS_PROXY:
                case SADB_EXT_KEY_AUTH:
                        /* XXX should to be check weak keys. */
                case SADB_EXT_KEY_ENCRYPT:
                        /* XXX should to be check weak keys. */
                case SADB_EXT_IDENTITY_SRC:
                case SADB_EXT_IDENTITY_DST:
                case SADB_EXT_SENSITIVITY:
                case SADB_EXT_PROPOSAL:
                case SADB_EXT_SUPPORTED_AUTH:
                case SADB_EXT_SUPPORTED_ENCRYPT:
                case SADB_EXT_SPIRANGE:
                case SADB_X_EXT_POLICY:
                case SADB_X_EXT_SA2:
                case SADB_X_EXT_NAT_T_TYPE:
                case SADB_X_EXT_NAT_T_SPORT:
                case SADB_X_EXT_NAT_T_DPORT:
                case SADB_X_EXT_NAT_T_OAI:
                case SADB_X_EXT_NAT_T_OAR:
                case SADB_X_EXT_NAT_T_FRAG:
                case SADB_X_EXT_SA_REPLAY:
                case SADB_X_EXT_NEW_ADDRESS_SRC:
                case SADB_X_EXT_NEW_ADDRESS_DST:
                case SADB_X_EXT_LFT_CUR_SW_OFFL:
                case SADB_X_EXT_LFT_CUR_HW_OFFL:
                case SADB_X_EXT_IF_HW_OFFL:
                        mhp[ext->sadb_ext_type] = (caddr_t)ext;
                        break;
                default:
                        __ipsec_errcode = EIPSEC_INVAL_EXTTYPE;
                        return -1;
                }

                p += PFKEY_EXTLEN(ext);
        }

        if (p != ep) {
                __ipsec_errcode = EIPSEC_INVAL_SADBMSG;
                return -1;
        }

        __ipsec_errcode = EIPSEC_NO_ERROR;
        return 0;
}

/*
 * check basic usage for sadb_msg,
 * NOTE: This routine is derived from netkey/key.c in KAME.
 * IN:  msg: pointer to message buffer.
 *      mhp: pointer to the buffer initialized like below:
 *
 *              caddr_t mhp[SADB_EXT_MAX + 1];
 *
 * OUT: -1: invalid.
 *       0: valid.
 */
int
pfkey_check(caddr_t *mhp)
{
        struct sadb_msg *msg;

        /* validity check */
        if (mhp == NULL || mhp[0] == NULL) {
                __ipsec_errcode = EIPSEC_INVAL_ARGUMENT;
                return -1;
        }

        msg = (struct sadb_msg *)mhp[0];

        /* check version */
        if (msg->sadb_msg_version != PF_KEY_V2) {
                __ipsec_errcode = EIPSEC_INVAL_VERSION;
                return -1;
        }

        /* check type */
        if (msg->sadb_msg_type > SADB_MAX) {
                __ipsec_errcode = EIPSEC_INVAL_MSGTYPE;
                return -1;
        }

        /* check SA type */
        switch (msg->sadb_msg_satype) {
        case SADB_SATYPE_UNSPEC:
                switch (msg->sadb_msg_type) {
                case SADB_GETSPI:
                case SADB_UPDATE:
                case SADB_ADD:
                case SADB_DELETE:
                case SADB_GET:
                case SADB_ACQUIRE:
                case SADB_EXPIRE:
                        __ipsec_errcode = EIPSEC_INVAL_SATYPE;
                        return -1;
                }
                break;
        case SADB_SATYPE_ESP:
        case SADB_SATYPE_AH:
        case SADB_X_SATYPE_IPCOMP:
        case SADB_X_SATYPE_TCPSIGNATURE:
                switch (msg->sadb_msg_type) {
                case SADB_X_SPDADD:
                case SADB_X_SPDDELETE:
                case SADB_X_SPDGET:
                case SADB_X_SPDDUMP:
                case SADB_X_SPDFLUSH:
                        __ipsec_errcode = EIPSEC_INVAL_SATYPE;
                        return -1;
                }
                break;
        case SADB_SATYPE_RSVP:
        case SADB_SATYPE_OSPFV2:
        case SADB_SATYPE_RIPV2:
        case SADB_SATYPE_MIP:
                __ipsec_errcode = EIPSEC_NOT_SUPPORTED;
                return -1;
        case 1: /* XXX: What does it do ? */
                if (msg->sadb_msg_type == SADB_X_PROMISC)
                        break;
                /*FALLTHROUGH*/
        default:
                __ipsec_errcode = EIPSEC_INVAL_SATYPE;
                return -1;
        }

        /* check field of upper layer protocol and address family */
        if (mhp[SADB_EXT_ADDRESS_SRC] != NULL
         && mhp[SADB_EXT_ADDRESS_DST] != NULL) {
                struct sadb_address *src0, *dst0;

                src0 = (struct sadb_address *)(mhp[SADB_EXT_ADDRESS_SRC]);
                dst0 = (struct sadb_address *)(mhp[SADB_EXT_ADDRESS_DST]);

                if (src0->sadb_address_proto != dst0->sadb_address_proto) {
                        __ipsec_errcode = EIPSEC_PROTO_MISMATCH;
                        return -1;
                }

                if (PFKEY_ADDR_SADDR(src0)->sa_family
                 != PFKEY_ADDR_SADDR(dst0)->sa_family) {
                        __ipsec_errcode = EIPSEC_FAMILY_MISMATCH;
                        return -1;
                }

                switch (PFKEY_ADDR_SADDR(src0)->sa_family) {
                case AF_INET:
                case AF_INET6:
                        break;
                default:
                        __ipsec_errcode = EIPSEC_INVAL_FAMILY;
                        return -1;
                }

                /*
                 * prefixlen == 0 is valid because there must be the case
                 * all addresses are matched.
                 */
        }

        __ipsec_errcode = EIPSEC_NO_ERROR;
        return 0;
}

/*
 * set data into sadb_msg.
 * `buf' must has been allocated sufficiently.
 */
static caddr_t
pfkey_setsadbmsg(caddr_t buf, caddr_t lim, u_int type, u_int tlen,
    u_int satype, u_int32_t seq, pid_t pid)
{
        struct sadb_msg *p;
        u_int len;

        p = (struct sadb_msg *)buf;
        len = sizeof(struct sadb_msg);

        if (buf + len > lim)
                return NULL;

        memset(p, 0, len);
        p->sadb_msg_version = PF_KEY_V2;
        p->sadb_msg_type = type;
        p->sadb_msg_errno = 0;
        p->sadb_msg_satype = satype;
        p->sadb_msg_len = PFKEY_UNIT64(tlen);
        p->sadb_msg_reserved = 0;
        p->sadb_msg_seq = seq;
        p->sadb_msg_pid = (u_int32_t)pid;

        return(buf + len);
}

/*
 * copy secasvar data into sadb_address.
 * `buf' must has been allocated sufficiently.
 */
static caddr_t
pfkey_setsadbsa(caddr_t buf, caddr_t lim, u_int32_t spi, u_int wsize,
    u_int auth, u_int enc, u_int32_t flags)
{
        struct sadb_sa *p;
        u_int len;

        p = (struct sadb_sa *)buf;
        len = sizeof(struct sadb_sa);

        if (buf + len > lim)
                return NULL;

        memset(p, 0, len);
        p->sadb_sa_len = PFKEY_UNIT64(len);
        p->sadb_sa_exttype = SADB_EXT_SA;
        p->sadb_sa_spi = spi;
        p->sadb_sa_replay = wsize > UINT8_MAX ? UINT8_MAX: wsize;
        p->sadb_sa_state = SADB_SASTATE_LARVAL;
        p->sadb_sa_auth = auth;
        p->sadb_sa_encrypt = enc;
        p->sadb_sa_flags = flags;

        return(buf + len);
}

/*
 * Set data into sadb_x_sa_replay.
 * `buf' must has been allocated sufficiently.
 */
static caddr_t
pfkey_setsadbxreplay(caddr_t buf, caddr_t lim, uint32_t wsize)
{
        struct sadb_x_sa_replay *p;
        u_int len;

        p = (struct sadb_x_sa_replay *)buf;
        len = sizeof(struct sadb_x_sa_replay);

        if (buf + len > lim)
                return (NULL);

        memset(p, 0, len);
        p->sadb_x_sa_replay_len = PFKEY_UNIT64(len);
        p->sadb_x_sa_replay_exttype = SADB_X_EXT_SA_REPLAY;
        /* Convert wsize from bytes to number of packets. */
        p->sadb_x_sa_replay_replay = wsize << 3;

        return (buf + len);
}

/*
 * set data into sadb_address.
 * `buf' must has been allocated sufficiently.
 * prefixlen is in bits.
 */
static caddr_t
pfkey_setsadbaddr(caddr_t buf, caddr_t lim, u_int exttype,
    struct sockaddr *saddr, u_int prefixlen, u_int ul_proto)
{
        struct sadb_address *p;
        u_int len;

        p = (struct sadb_address *)buf;
        len = sizeof(struct sadb_address) + PFKEY_ALIGN8(saddr->sa_len);

        if (buf + len > lim)
                return NULL;

        memset(p, 0, len);
        p->sadb_address_len = PFKEY_UNIT64(len);
        p->sadb_address_exttype = exttype & 0xffff;
        p->sadb_address_proto = ul_proto & 0xff;
        p->sadb_address_prefixlen = prefixlen;
        p->sadb_address_reserved = 0;

        memcpy(p + 1, saddr, saddr->sa_len);

        return(buf + len);
}

/*
 * set sadb_key structure after clearing buffer with zero.
 * OUT: the pointer of buf + len.
 */
static caddr_t
pfkey_setsadbkey(caddr_t buf, caddr_t lim, u_int type, caddr_t key, u_int keylen)
{
        struct sadb_key *p;
        u_int len;

        p = (struct sadb_key *)buf;
        len = sizeof(struct sadb_key) + PFKEY_ALIGN8(keylen);

        if (buf + len > lim)
                return NULL;

        memset(p, 0, len);
        p->sadb_key_len = PFKEY_UNIT64(len);
        p->sadb_key_exttype = type;
        p->sadb_key_bits = keylen << 3;
        p->sadb_key_reserved = 0;

        memcpy(p + 1, key, keylen);

        return buf + len;
}

/*
 * set sadb_lifetime structure after clearing buffer with zero.
 * OUT: the pointer of buf + len.
 */
static caddr_t
pfkey_setsadblifetime(caddr_t buf, caddr_t lim, u_int type, u_int32_t l_alloc,
    u_int32_t l_bytes, u_int32_t l_addtime, u_int32_t l_usetime)
{
        struct sadb_lifetime *p;
        u_int len;

        p = (struct sadb_lifetime *)buf;
        len = sizeof(struct sadb_lifetime);

        if (buf + len > lim)
                return NULL;

        memset(p, 0, len);
        p->sadb_lifetime_len = PFKEY_UNIT64(len);
        p->sadb_lifetime_exttype = type;

        switch (type) {
        case SADB_EXT_LIFETIME_SOFT:
                p->sadb_lifetime_allocations
                        = (l_alloc * soft_lifetime_allocations_rate) /100;
                p->sadb_lifetime_bytes
                        = (l_bytes * soft_lifetime_bytes_rate) /100;
                p->sadb_lifetime_addtime
                        = (l_addtime * soft_lifetime_addtime_rate) /100;
                p->sadb_lifetime_usetime
                        = (l_usetime * soft_lifetime_usetime_rate) /100;
                break;
        case SADB_EXT_LIFETIME_HARD:
                p->sadb_lifetime_allocations = l_alloc;
                p->sadb_lifetime_bytes = l_bytes;
                p->sadb_lifetime_addtime = l_addtime;
                p->sadb_lifetime_usetime = l_usetime;
                break;
        }

        return buf + len;
}

/*
 * copy secasvar data into sadb_address.
 * `buf' must has been allocated sufficiently.
 */
static caddr_t
pfkey_setsadbxsa2(caddr_t buf, caddr_t lim, u_int32_t mode0, u_int32_t reqid)
{
        struct sadb_x_sa2 *p;
        u_int8_t mode = mode0 & 0xff;
        u_int len;

        p = (struct sadb_x_sa2 *)buf;
        len = sizeof(struct sadb_x_sa2);

        if (buf + len > lim)
                return NULL;

        memset(p, 0, len);
        p->sadb_x_sa2_len = PFKEY_UNIT64(len);
        p->sadb_x_sa2_exttype = SADB_X_EXT_SA2;
        p->sadb_x_sa2_mode = mode;
        p->sadb_x_sa2_reqid = reqid;

        return(buf + len);
}