/*      $NetBSD: sctp_asconf.c,v 1.14 2024/04/11 07:34:37 knakahara Exp $ */
/*      $KAME: sctp_asconf.c,v 1.25 2005/06/16 20:44:24 jinmei Exp $    */

/*
 * Copyright (c) 2001, 2002, 2003, 2004 Cisco Systems, Inc.
 * 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 CISCO SYSTEMS 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 CISCO SYSTEMS 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sctp_asconf.c,v 1.14 2024/04/11 07:34:37 knakahara Exp $");

#ifdef _KERNEL_OPT
#include "opt_ipsec.h"
#include "opt_inet.h"
#include "opt_sctp.h"
#endif /* _KERNEL_OPT */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>

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

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

#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
#endif /* INET6 */

#include <netinet/in_pcb.h>

#include <netinet/sctp_var.h>
#include <netinet/sctp_pcb.h>
#include <netinet/sctp_header.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_asconf.h>
#include <netinet/sctp_route.h>

/*
 * debug flags:
 *   SCTP_DEBUG_ASCONF1: protocol info, general info and errors
 *   SCTP_DEBUG_ASCONF2: detailed info
 */
#ifdef SCTP_DEBUG
extern u_int32_t sctp_debug_on;
#endif /* SCTP_DEBUG */

/*
 * draft-ietf-tsvwg-addip-sctp
 *
 * Address management only currently supported
 * For the bound all case:
 *      the asoc local addr list is always a "DO NOT USE" list
 * For the subset bound case:
 *      If ASCONFs are allowed:
 *              the endpoint local addr list is the usable address list
 *              the asoc local addr list is the "DO NOT USE" list
 *      If ASCONFs are not allowed:
 *              the endpoint local addr list is the default usable list
 *              the asoc local addr list is the usable address list
 *
 * An ASCONF parameter queue exists per asoc which holds the pending
 * address operations.  Lists are updated upon receipt of ASCONF-ACK.
 *
 * Deleted addresses are always immediately removed from the lists as
 * they will (shortly) no longer exist in the kernel.  We send ASCONFs
 * as a courtesy, only if allowed.
 */

/*
 * ASCONF parameter processing
 * response_required: set if a reply is required (eg. SUCCESS_REPORT)
 * returns a mbuf to an "error" response parameter or NULL/"success" if ok
 * FIX: allocating this many mbufs on the fly is pretty inefficient...
 */

static struct mbuf *
sctp_asconf_success_response(uint32_t id)
{
        struct mbuf *m_reply = NULL;
        struct sctp_asconf_paramhdr *aph;

        MGET(m_reply, M_DONTWAIT, MT_DATA);
        if (m_reply == NULL) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_success_response: couldn't get mbuf!\n");
                }
#endif /* SCTP_DEBUG */
                return NULL;
        }
        aph = mtod(m_reply, struct sctp_asconf_paramhdr *);
        aph->correlation_id = id;
        aph->ph.param_type = htons(SCTP_SUCCESS_REPORT);
        aph->ph.param_length = sizeof(struct sctp_asconf_paramhdr);
        m_reply->m_len = aph->ph.param_length;
        aph->ph.param_length = htons(aph->ph.param_length);

        return m_reply;
}

static struct mbuf *
sctp_asconf_error_response(uint32_t id, uint16_t cause, uint8_t *error_tlv,
    uint16_t tlv_length)
{
        struct mbuf *m_reply = NULL;
        struct sctp_asconf_paramhdr *aph;
        struct sctp_error_cause *error;
        uint8_t *tlv;

        MGET(m_reply, M_DONTWAIT, MT_DATA);
        if (m_reply == NULL) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_error_response: couldn't get mbuf!\n");
                }
#endif /* SCTP_DEBUG */
                return NULL;
        }
        aph = mtod(m_reply, struct sctp_asconf_paramhdr *);
        error = (struct sctp_error_cause *)(aph + 1);

        aph->correlation_id = id;
        aph->ph.param_type = htons(SCTP_ERROR_CAUSE_IND);
        error->code = htons(cause);
        error->length = tlv_length + sizeof(struct sctp_error_cause);
        aph->ph.param_length = error->length +
            sizeof(struct sctp_asconf_paramhdr);

        if (aph->ph.param_length > MLEN) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_error_response: tlv_length (%xh) too big\n",
                            tlv_length);
                }
#endif /* SCTP_DEBUG */
                sctp_m_freem(m_reply);  /* discard */
                return NULL;
        }

        if (error_tlv != NULL) {
                tlv = (uint8_t *)(error + 1);
                memcpy(tlv, error_tlv, tlv_length);
        }

        m_reply->m_len = aph->ph.param_length;
        error->length = htons(error->length);
        aph->ph.param_length = htons(aph->ph.param_length);

        return m_reply;
}

static struct mbuf *
sctp_process_asconf_add_ip(struct sctp_asconf_paramhdr *aph,
    struct sctp_tcb *stcb, int response_required)
{
        struct mbuf *m_reply = NULL;
        struct sockaddr_storage sa_store;
        struct sctp_ipv4addr_param *v4addr;
        uint16_t param_type, param_length, aparam_length;
        struct sockaddr *sa;
        struct sockaddr_in *sin;
#ifdef INET6
        struct sockaddr_in6 *sin6;
        struct sctp_ipv6addr_param *v6addr;
#endif /* INET6 */

        aparam_length = ntohs(aph->ph.param_length);
        v4addr = (struct sctp_ipv4addr_param *)(aph + 1);
#ifdef INET6
        v6addr = (struct sctp_ipv6addr_param *)(aph + 1);
#endif /* INET6 */
        param_type = ntohs(v4addr->ph.param_type);
        param_length = ntohs(v4addr->ph.param_length);

        sa = (struct sockaddr *)&sa_store;
        switch (param_type) {
        case SCTP_IPV4_ADDRESS:
                if (param_length != sizeof(struct sctp_ipv4addr_param)) {
                        /* invalid param size */
                        return NULL;
                }
                sin = (struct sockaddr_in *)&sa_store;
                memset(sin, 0, sizeof(*sin));
                sin->sin_family = AF_INET;
                sin->sin_len = sizeof(struct sockaddr_in);
                sin->sin_port = stcb->rport;
                sin->sin_addr.s_addr = v4addr->addr;
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_add_ip: adding ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
                break;
        case SCTP_IPV6_ADDRESS:
#ifdef INET6
                if (param_length != sizeof(struct sctp_ipv6addr_param)) {
                        /* invalid param size */
                        return NULL;
                }
                sin6 = (struct sockaddr_in6 *)&sa_store;
                memset(sin6, 0, sizeof(*sin6));
                sin6->sin6_family = AF_INET6;
                sin6->sin6_len = sizeof(struct sockaddr_in6);
                sin6->sin6_port = stcb->rport;
                memcpy((void *)&sin6->sin6_addr, v6addr->addr,
                    sizeof(struct in6_addr));
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_add_ip: adding ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
#else
                /* IPv6 not enabled! */
                /* FIX ME: currently sends back an invalid param error */
                m_reply = sctp_asconf_error_response(aph->correlation_id,
                    SCTP_ERROR_INVALID_PARAM, (uint8_t *)aph, aparam_length);
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_add_ip: v6 disabled- skipping ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
                return m_reply;
#endif /* INET6 */
                break;
        default:
                m_reply = sctp_asconf_error_response(aph->correlation_id,
                    SCTP_ERROR_UNRESOLVABLE_ADDR, (uint8_t *)aph,
                    aparam_length);
                return m_reply;
        } /* end switch */

        /* add the address */
        if (sctp_add_remote_addr(stcb, sa, 0, 6) != 0) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_add_ip: error adding address\n");
                }
#endif /* SCTP_DEBUG */
                m_reply = sctp_asconf_error_response(aph->correlation_id,
                    SCTP_ERROR_RESOURCE_SHORTAGE, (uint8_t *)aph,
                    aparam_length);
        } else {
                /* notify upper layer */
                sctp_ulp_notify(SCTP_NOTIFY_ASCONF_ADD_IP, stcb, 0, sa);
                if (response_required) {
                        m_reply =
                            sctp_asconf_success_response(aph->correlation_id);
                }
        }

        return m_reply;
}

static struct mbuf *
sctp_process_asconf_delete_ip(struct mbuf *m, struct sctp_asconf_paramhdr *aph,
    struct sctp_tcb *stcb, int response_required)
{
        struct mbuf *m_reply = NULL;
        struct sockaddr_storage sa_store, sa_source;
        struct sctp_ipv4addr_param *v4addr;
        uint16_t param_type, param_length, aparam_length;
        struct sockaddr *sa;
        struct sockaddr_in *sin;
        struct ip *iph;
        int result;
#ifdef INET6
        struct sockaddr_in6 *sin6;
        struct sctp_ipv6addr_param *v6addr;
#endif /* INET6 */

        aparam_length = ntohs(aph->ph.param_length);
        v4addr = (struct sctp_ipv4addr_param *)(aph + 1);
#ifdef INET6
        v6addr = (struct sctp_ipv6addr_param *)(aph + 1);
#endif /* INET6 */
        param_type = ntohs(v4addr->ph.param_type);
        param_length = ntohs(v4addr->ph.param_length);

        /* get the source IP address for deletion check */
        iph = mtod(m, struct ip *);
        if (iph->ip_v == IPVERSION) {
                /* IPv4 source */
                sin = (struct sockaddr_in *)&sa_source;
                memset(sin, 0, sizeof(*sin));
                sin->sin_family = AF_INET;
                sin->sin_len = sizeof(struct sockaddr_in);
                sin->sin_port = stcb->rport;
                sin->sin_addr.s_addr = iph->ip_src.s_addr;
        }
#ifdef INET6
        else if (iph->ip_v == (IPV6_VERSION >> 4)) {
                /* IPv6 source */
                struct ip6_hdr *ip6;

                sin6 = (struct sockaddr_in6 *)&sa_source;
                memset(sin6, 0, sizeof(*sin6));
                sin6->sin6_family = AF_INET6;
                sin6->sin6_len = sizeof(struct sockaddr_in6);
                sin6->sin6_port = stcb->rport;
                ip6 = mtod(m, struct ip6_hdr *);
                sin6->sin6_addr = ip6->ip6_src;
        }
#endif /* INET6 */
        else
                return NULL;

        sa = (struct sockaddr *)&sa_store;
        switch (param_type) {
        case SCTP_IPV4_ADDRESS:
                if (param_length != sizeof(struct sctp_ipv4addr_param)) {
                        /* invalid param size */
                        return NULL;
                }
                sin = (struct sockaddr_in *)&sa_store;
                memset(sin, 0, sizeof(*sin));
                sin->sin_family = AF_INET;
                sin->sin_len = sizeof(struct sockaddr_in);
                sin->sin_port = stcb->rport;
                sin->sin_addr.s_addr = v4addr->addr;
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_delete_ip: deleting ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
                break;
        case SCTP_IPV6_ADDRESS:
                if (param_length != sizeof(struct sctp_ipv6addr_param)) {
                        /* invalid param size */
                        return NULL;
                }
#ifdef INET6
                sin6 = (struct sockaddr_in6 *)&sa_store;
                memset(sin6, 0, sizeof(*sin6));
                sin6->sin6_family = AF_INET6;
                sin6->sin6_len = sizeof(struct sockaddr_in6);
                sin6->sin6_port = stcb->rport;
                memcpy(&sin6->sin6_addr, v6addr->addr,
                    sizeof(struct in6_addr));
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_delete_ip: deleting ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
#else
                /* IPv6 not enabled!  No "action" needed; just ack it */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_delete_ip: v6 disabled- ignoring: ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
                /* just respond with a "success" ASCONF-ACK */
                return NULL;
#endif /* INET6 */
                break;
        default:
                m_reply = sctp_asconf_error_response(aph->correlation_id,
                    SCTP_ERROR_UNRESOLVABLE_ADDR, (uint8_t *)aph,
                    aparam_length);
                return m_reply;
        } /* end switch */

        /* make sure the source address is not being deleted */
        if ((memcmp(sa, &sa_source, sizeof(struct sockaddr_in)) == 0)
#ifdef INET6
            || (memcmp(sa, &sa_source, sizeof(struct sockaddr_in6)) == 0)
#endif /* INET6 */
                ) {
                /* trying to delete the source address! */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_delete_ip: tried to delete source addr\n");
                }
#endif /* SCTP_DEBUG */
                m_reply = sctp_asconf_error_response(aph->correlation_id,
                    SCTP_ERROR_DELETE_SOURCE_ADDR, (uint8_t *)aph,
                    aparam_length);
                return m_reply;
        }

        /* delete the address */
        result = sctp_del_remote_addr(stcb, sa);
        /*
         * note if result == -2, the address doesn't exist in the asoc
         * but since it's being deleted anyways, we just ack the delete
         * -- but this probably means something has already gone awry
         */
        if (result == -1) {
                /* only one address in the asoc */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_delete_ip: tried to delete last IP addr!\n");
                }
#endif /* SCTP_DEBUG */
                m_reply = sctp_asconf_error_response(aph->correlation_id,
                    SCTP_ERROR_DELETE_LAST_ADDR, (uint8_t *)aph,
                    aparam_length);
        } else {
                /* notify upper layer */
                sctp_ulp_notify(SCTP_NOTIFY_ASCONF_DELETE_IP, stcb, 0, sa);
        }

        if (response_required) {
                m_reply = sctp_asconf_success_response(aph->correlation_id);
        }
        return m_reply;
}

static struct mbuf *
sctp_process_asconf_set_primary(struct sctp_asconf_paramhdr *aph,
    struct sctp_tcb *stcb, int response_required)
{
        struct mbuf *m_reply = NULL;
        struct sockaddr_storage sa_store;
        struct sctp_ipv4addr_param *v4addr;
        uint16_t param_type, param_length, aparam_length;
        struct sockaddr *sa;
        struct sockaddr_in *sin;
#ifdef INET6
        struct sockaddr_in6 *sin6;
        struct sctp_ipv6addr_param *v6addr;
#endif /* INET6 */

        aparam_length = ntohs(aph->ph.param_length);
        v4addr = (struct sctp_ipv4addr_param *)(aph + 1);
#ifdef INET6
        v6addr = (struct sctp_ipv6addr_param *)(aph + 1);
#endif /* INET6 */
        param_type = ntohs(v4addr->ph.param_type);
        param_length = ntohs(v4addr->ph.param_length);

        sa = (struct sockaddr *)&sa_store;
        switch (param_type) {
        case SCTP_IPV4_ADDRESS:
                if (param_length != sizeof(struct sctp_ipv4addr_param)) {
                        /* invalid param size */
                        return NULL;
                }
                sin = (struct sockaddr_in *)&sa_store;
                memset(sin, 0, sizeof(*sin));
                sin->sin_family = AF_INET;
                sin->sin_len = sizeof(struct sockaddr_in);
                sin->sin_addr.s_addr = v4addr->addr;
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_set_primary: ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
                break;
        case SCTP_IPV6_ADDRESS:
                if (param_length != sizeof(struct sctp_ipv6addr_param)) {
                        /* invalid param size */
                        return NULL;
                }
#ifdef INET6
                sin6 = (struct sockaddr_in6 *)&sa_store;
                memset(sin6, 0, sizeof(*sin6));
                sin6->sin6_family = AF_INET6;
                sin6->sin6_len = sizeof(struct sockaddr_in6);
                memcpy((void *)&sin6->sin6_addr, v6addr->addr,
                    sizeof(struct in6_addr));
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_set_primary: ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
#else
                /* IPv6 not enabled!  No "action" needed; just ack it */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_set_primary: v6 disabled- ignoring: ");
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
                /* just respond with a "success" ASCONF-ACK */
                return NULL;
#endif /* INET6 */
                break;
        default:
                m_reply = sctp_asconf_error_response(aph->correlation_id,
                    SCTP_ERROR_UNRESOLVABLE_ADDR, (uint8_t *)aph,
                    aparam_length);
                return m_reply;
        } /* end switch */

        /* set the primary address */
        if (sctp_set_primary_addr(stcb, sa, NULL) == 0) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_set_primary: primary address set\n");
                }
#endif /* SCTP_DEBUG */
                /* notify upper layer */
                sctp_ulp_notify(SCTP_NOTIFY_ASCONF_SET_PRIMARY, stcb, 0, sa);

                if (response_required) {
                        m_reply = sctp_asconf_success_response(aph->correlation_id);
                }
        } else {
                /* couldn't set the requested primary address! */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_asconf_set_primary: set primary failed!\n");
                }
#endif /* SCTP_DEBUG */
                /* must have been an invalid address, so report */
                m_reply = sctp_asconf_error_response(aph->correlation_id,
                    SCTP_ERROR_UNRESOLVABLE_ADDR, (uint8_t *)aph,
                    aparam_length);
        }

        return m_reply;
}

/*
 * handles an ASCONF chunk
 * if all parameters are processed ok, send a plain (empty) ASCONF-ACK
 */
void
sctp_handle_asconf(struct mbuf *m, unsigned int offset, struct sctp_asconf_chunk *cp,
    struct sctp_tcb *stcb, struct sctp_nets *net)
{
        struct sctp_association *asoc;
        uint32_t serial_num;
        struct mbuf *m_ack, *m_result, *m_tail;
        struct sctp_asconf_ack_chunk *ack_cp;
        struct sctp_asconf_paramhdr *aph, *ack_aph;
        struct sctp_ipv6addr_param *p_addr;
        unsigned int asconf_limit;
        int error = 0;          /* did an error occur? */
        /* asconf param buffer */
        static u_int8_t aparam_buf[DEFAULT_PARAM_BUFFER];

        /* verify minimum length */
        if (ntohs(cp->ch.chunk_length) < sizeof(struct sctp_asconf_chunk)) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("handle_asconf: chunk too small = %xh\n",
                            ntohs(cp->ch.chunk_length));
                }
#endif /* SCTP_DEBUG */
                return;
        }

        asoc = &stcb->asoc;
        serial_num = ntohl(cp->serial_number);

        if (serial_num == asoc->asconf_seq_in) {
                /* got a duplicate ASCONF */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("handle_asconf: got duplicate serial number = %xh\n",
                               serial_num);
                }
#endif /* SCTP_DEBUG */
                /* resend last ASCONF-ACK... */
                sctp_send_asconf_ack(stcb, 1);
                return;
        } else if (serial_num != (asoc->asconf_seq_in + 1)) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("handle_asconf: incorrect serial number = %xh (expected next = %xh)\n",
                            serial_num, asoc->asconf_seq_in+1);
                }
#endif /* SCTP_DEBUG */
                return;
        }

        /* it's the expected "next" sequence number, so process it */
        asoc->asconf_seq_in = serial_num;       /* update sequence */
        /* get length of all the param's in the ASCONF */
        asconf_limit = offset + ntohs(cp->ch.chunk_length);
#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                printf("handle_asconf: asconf_limit=%u, sequence=%xh\n",
                    asconf_limit, serial_num);
        }
#endif /* SCTP_DEBUG */
        if (asoc->last_asconf_ack_sent != NULL) {
                /* free last ASCONF-ACK message sent */
                sctp_m_freem(asoc->last_asconf_ack_sent);
                asoc->last_asconf_ack_sent = NULL;
        }
        MGETHDR(m_ack, M_DONTWAIT, MT_DATA);
        if (m_ack == NULL) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("handle_asconf: couldn't get mbuf!\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }
        m_tail = m_ack;         /* current reply chain's tail */

        /* fill in ASCONF-ACK header */
        ack_cp = mtod(m_ack, struct sctp_asconf_ack_chunk *);
        ack_cp->ch.chunk_type = SCTP_ASCONF_ACK;
        ack_cp->ch.chunk_flags = 0;
        ack_cp->serial_number = htonl(serial_num);
        /* set initial lengths (eg. just an ASCONF-ACK), ntohx at the end! */
        m_ack->m_len = sizeof(struct sctp_asconf_ack_chunk);
        ack_cp->ch.chunk_length = sizeof(struct sctp_asconf_ack_chunk);
        m_ack->m_pkthdr.len = sizeof(struct sctp_asconf_ack_chunk);

        /* skip the lookup address parameter */
        offset += sizeof(struct sctp_asconf_chunk);
        p_addr = (struct sctp_ipv6addr_param *)sctp_m_getptr(m, offset, sizeof(struct sctp_paramhdr), (uint8_t *)&aparam_buf);
        if (p_addr == NULL) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("handle_asconf: couldn't get lookup addr!\n");
                }
#endif /* SCTP_DEBUG */

                /* respond with a missing/invalid mandatory parameter error */
                return;
        }
        /* param_length is already validated in process_control... */
        offset += ntohs(p_addr->ph.param_length);   /* skip lookup addr */

        /* get pointer to first asconf param in ASCONF */
        aph = (struct sctp_asconf_paramhdr *)sctp_m_getptr(m, offset, sizeof(struct sctp_asconf_paramhdr), (uint8_t *)&aparam_buf);
        /* get pointer to first asconf param in ASCONF-ACK */
        if (aph == NULL) {
                printf("Gak in asconf\n");
                return;
        }
        ack_aph = (struct sctp_asconf_paramhdr *)(mtod(m_ack, vaddr_t) + sizeof(struct sctp_asconf_ack_chunk));
        if (ack_aph == NULL) {
                printf("Gak in asconf2\n");
                return;
        }

        /* process through all parameters */
        while (aph != NULL) {
                unsigned int param_length, param_type;

                param_type = ntohs(aph->ph.param_type);
                param_length = ntohs(aph->ph.param_length);
                if (offset + param_length > asconf_limit) {
                        /* parameter goes beyond end of chunk! */
                        sctp_m_freem(m_ack);
                        return;
                }
                m_result = NULL;

                if (param_length > sizeof(aparam_buf)) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("handle_asconf: param length (%u) larger than buffer size!\n", param_length);
                        }
#endif /* SCTP_DEBUG */
                        sctp_m_freem(m_ack);
                        return;
                }
                if (param_length <= sizeof(struct sctp_paramhdr)) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("handle_asconf: param length (%u) too short\n", param_length);
                        }
#endif /* SCTP_DEBUG */
                        sctp_m_freem(m_ack);
                }

                /* get the entire parameter */
                aph = (struct sctp_asconf_paramhdr *)sctp_m_getptr(m, offset, param_length, aparam_buf);
                if (aph == NULL) {
                        printf("Gag\n");
                        sctp_m_freem(m_ack);
                        return;
                }
                switch (param_type) {
                case SCTP_ADD_IP_ADDRESS:
                        asoc->peer_supports_asconf = 1;
                        m_result = sctp_process_asconf_add_ip(aph, stcb, error);
                        break;
                case SCTP_DEL_IP_ADDRESS:
                        asoc->peer_supports_asconf = 1;
                        m_result = sctp_process_asconf_delete_ip(m, aph, stcb,
                            error);
                        break;
                case SCTP_ERROR_CAUSE_IND:
                        /* not valid in an ASCONF chunk */
                        break;
                case SCTP_SET_PRIM_ADDR:
                        asoc->peer_supports_asconf_setprim = 1;
                        m_result = sctp_process_asconf_set_primary(aph, stcb,
                            error);
                        break;
                case SCTP_SUCCESS_REPORT:
                        /* not valid in an ASCONF chunk */
                        break;
                case SCTP_ULP_ADAPTION:
                        /* FIX */
                        break;
                default:
                        if ((param_type & 0x8000) == 0) {
                                /* Been told to STOP at this param */
                                asconf_limit = offset;
                                /* FIX FIX - We need to call sctp_arethere_unrecognized_parameters()
                                 * to get a operr and send it for any param's with the
                                 * 0x4000 bit set OR do it here ourselves... note we still
                                 * must STOP if the 0x8000 bit is clear.
                                 */
                        }
                        /* unknown/invalid param type */
                        break;
                } /* switch */

                /* add any (error) result to the reply mbuf chain */
                if (m_result != NULL) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("handle_asconf: adding reply...\n");
                        }
#endif /* SCTP_DEBUG */
                        m_tail->m_next = m_result;
                        m_tail = m_result;
                        /* update lengths, make sure it's aligned too */
                        m_result->m_len = SCTP_SIZE32(m_result->m_len);
                        m_ack->m_pkthdr.len += m_result->m_len;
                        ack_cp->ch.chunk_length += m_result->m_len;
                        /* set flag to force success reports */
                        error = 1;
                }

                offset += SCTP_SIZE32(param_length);
                /* update remaining ASCONF message length to process */
                if (offset >= asconf_limit) {
                        /* no more data in the mbuf chain */
                        break;
                }
                /* get pointer to next asconf param */
                aph = (struct sctp_asconf_paramhdr *)sctp_m_getptr(m, offset,
                    sizeof(struct sctp_asconf_paramhdr),
                    (uint8_t *)&aparam_buf);
                if (aph == NULL) {
                        /* can't get an asconf paramhdr */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("handle_asconf: can't get asconf param hdr!\n");
                        }
#endif /* SCTP_DEBUG */
                        /* FIX ME - add error here... */
                }
        } /* while */

        ack_cp->ch.chunk_length = htons(ack_cp->ch.chunk_length);
        /* save the ASCONF-ACK reply */
        asoc->last_asconf_ack_sent = m_ack;
        /* and send (a new one) it out... */
        sctp_send_asconf_ack(stcb, 0);
}

/*
 * does the address match?
 * returns 0 if not, 1 if so
 */
static uint32_t
sctp_asconf_addr_match(struct sctp_asconf_addr *aa, struct sockaddr *sa)
{
#ifdef INET6
        if (sa->sa_family == AF_INET6) {
                /* IPv6 sa address */
                /* XXX scopeid */
                struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
                if ((aa->ap.addrp.ph.param_type == SCTP_IPV6_ADDRESS) &&
                    (memcmp(&aa->ap.addrp.addr, &sin6->sin6_addr,
                            sizeof(struct in6_addr)) == 0)) {
                        return (1);
                }
        } else
#endif /* INET6 */
        if (sa->sa_family == AF_INET) {
                /* IPv4 sa address */
                struct sockaddr_in *sin = (struct sockaddr_in *)sa;
                if ((aa->ap.addrp.ph.param_type == SCTP_IPV4_ADDRESS) &&
                    (memcmp(&aa->ap.addrp.addr, &sin->sin_addr,
                            sizeof(struct in_addr)) == 0)) {
                        return (1);
                }
        }
        return (0);
}

/*
 * Cleanup for non-responded/OP ERR'd ASCONF
 */
void
sctp_asconf_cleanup(struct sctp_tcb *stcb, struct sctp_nets *net)
{
#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                printf("asconf_cleanup: marking peer ASCONF incapable and cleaning up\n");
        }
#endif /* SCTP_DEBUG */
        /* mark peer as ASCONF incapable */
        stcb->asoc.peer_supports_asconf = 0;
        stcb->asoc.peer_supports_asconf_setprim = 0;
        /*
         * clear out any existing asconfs going out
         */
        sctp_timer_stop(SCTP_TIMER_TYPE_ASCONF, stcb->sctp_ep, stcb, net);
        stcb->asoc.asconf_seq_out++;
        /* remove the old ASCONF on our outbound queue */
        sctp_toss_old_asconf(stcb);
}

/*
 * process an ADD/DELETE IP ack from peer
 * ifa:  corresponding ifaddr to the address being added/deleted
 * type: SCTP_ADD_IP_ADDRESS or SCTP_DEL_IP_ADDRESS
 * flag: 1=success, 0=failure
 */
static void
sctp_asconf_addr_mgmt_ack(struct sctp_tcb *stcb, struct ifaddr *addr,
    uint16_t type, uint32_t flag)
{

        /*
         * do the necessary asoc list work-
         * if we get a failure indication, leave the address on the
         *   "do not use" asoc list
         * if we get a success indication, remove the address from
         *   the list
         */
        /*
         * Note: this will only occur for ADD_IP_ADDRESS, since
         * DEL_IP_ADDRESS is never actually added to the list...
         */
        if (flag) {
                /* success case, so remove from the list */
                sctp_del_local_addr_assoc(stcb, addr);
        }
        /* else, leave it on the list */
}

/*
 * add an asconf add/delete IP address parameter to the queue
 * type = SCTP_ADD_IP_ADDRESS, SCTP_DEL_IP_ADDRESS, SCTP_SET_PRIM_ADDR
 * returns 0 if completed, non-zero if not completed
 * NOTE: if adding, but delete already scheduled (and not yet
 *      sent out), simply remove from queue.  Same for deleting
 *      an address already scheduled for add.  If a duplicate
 *      operation is found, ignore the new one.
 */
static uint32_t
sctp_asconf_queue_add(struct sctp_tcb *stcb, struct ifaddr *ifa, uint16_t type)
{
        struct sctp_asconf_addr *aa, *aa_next;
#ifdef SCTP_DEBUG
        char buf[128];  /* for address in string format */
#endif /* SCTP_DEBUG */

        /* see if peer supports ASCONF */
        if (stcb->asoc.peer_supports_asconf == 0) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_queue_add: peer doesn't support ASCONF\n");
                }
#endif /* SCTP_DEBUG */
                return (-1);
        }

        /* make sure the request isn't already in the queue */
        for (aa=TAILQ_FIRST(&stcb->asoc.asconf_queue); aa!=NULL; aa=aa_next) {
                aa_next = TAILQ_NEXT(aa, next);
                /* address match? */
                if (sctp_asconf_addr_match(aa, ifa->ifa_addr) == 0)
                        continue;
                /* is the request already in queue (sent or not) */
                if (aa->ap.aph.ph.param_type == type) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("asconf_queue_add: request already exists\n");
                        }
#endif /* SCTP_DEBUG */
                        return (-1);
                }
                /* is the negative request already in queue, and not sent */
                if (aa->sent == 0 &&
                    /* add requested, delete already queued */
                    ((type == SCTP_ADD_IP_ADDRESS &&
                      aa->ap.aph.ph.param_type == SCTP_DEL_IP_ADDRESS) ||
                     /* delete requested, add already queued */
                     (type == SCTP_DEL_IP_ADDRESS &&
                      aa->ap.aph.ph.param_type == SCTP_ADD_IP_ADDRESS))) {
                        /* delete the existing entry in the queue */
                        TAILQ_REMOVE(&stcb->asoc.asconf_queue, aa, next);
                        /* take the entry off the appropriate list */
                        sctp_asconf_addr_mgmt_ack(stcb, aa->ifa, type, 1);
                        /* free the entry */
                        free(aa, M_PCB);

#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("asconf_queue_add: removing 'opposite' queued request\n");
                        }
#endif /* SCTP_DEBUG */
                        return (-1);
                }
        } /* for each aa */

        /* adding new request to the queue */
        aa = malloc(sizeof(*aa), M_PCB, M_NOWAIT);
        if (aa == NULL) {
                /* didn't get memory */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_queue_add: failed to get memory!\n");
                }
#endif /* SCTP_DEBUG */
                return (-1);
        }
        /* fill in asconf address parameter fields */
        /* top level elements are "networked" during send */
        aa->ap.aph.ph.param_type = type;
        aa->ifa = ifa;
        /* correlation_id filled in during send routine later... */
        if (ifa->ifa_addr->sa_family == AF_INET6) {
                /* IPv6 address */
#ifdef SCTP_DEBUG
                char ip6buf[INET6_ADDRSTRLEN];
#endif
                struct sockaddr_in6 *sin6;

                sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
                aa->ap.addrp.ph.param_type = SCTP_IPV6_ADDRESS;
                aa->ap.addrp.ph.param_length = (sizeof(struct sctp_ipv6addr_param));
                aa->ap.aph.ph.param_length =
                    sizeof(struct sctp_asconf_paramhdr) +
                    sizeof(struct sctp_ipv6addr_param);
                memcpy(&aa->ap.addrp.addr, &sin6->sin6_addr,
                    sizeof(struct in6_addr));
#ifdef SCTP_DEBUG
                strlcpy(buf, IN6_PRINT(ip6buf, &sin6->sin6_addr), sizeof(buf));
#endif /* SCTP_DEBUG */

        } else if (ifa->ifa_addr->sa_family == AF_INET) {
                /* IPv4 address */
                struct sockaddr_in *sin = (struct sockaddr_in *)ifa->ifa_addr;
                aa->ap.addrp.ph.param_type = SCTP_IPV4_ADDRESS;
                aa->ap.addrp.ph.param_length = (sizeof(struct sctp_ipv4addr_param));
                aa->ap.aph.ph.param_length =
                    sizeof(struct sctp_asconf_paramhdr) +
                    sizeof(struct sctp_ipv4addr_param);
                memcpy(&aa->ap.addrp.addr, &sin->sin_addr,
                    sizeof(struct in_addr));
#ifdef SCTP_DEBUG
                strlcpy(buf, inet_ntoa(sin->sin_addr), sizeof(buf));
#endif /* SCTP_DEBUG */
        } else {
                /* invalid family! */
                return (-1);
        }
        aa->sent = 0;                   /* clear sent flag */

        /*
         * if we are deleting an address it should go out last
         * otherwise, add it to front of the pending queue
         */
        if (type == SCTP_ADD_IP_ADDRESS) {
                /* add goes to the front of the queue */
                TAILQ_INSERT_HEAD(&stcb->asoc.asconf_queue, aa, next);
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_queue_add: appended asconf ADD_IP_ADDRESS: %s\n", buf);
                }
#endif /* SCTP_DEBUG */
        } else {
                /* delete and set primary goes to the back of the queue */
                TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa, next);
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        if (type == SCTP_DEL_IP_ADDRESS) {
                                printf("asconf_queue_add: inserted asconf DEL_IP_ADDRESS: %s\n", buf);
                        } else {
                                printf("asconf_queue_add: inserted asconf SET_PRIM_ADDR: %s\n", buf);
                        }
                }
#endif /* SCTP_DEBUG */
        }

        return (0);
}

/*
 * add an asconf add/delete IP address parameter to the queue by addr
 * type = SCTP_ADD_IP_ADDRESS, SCTP_DEL_IP_ADDRESS, SCTP_SET_PRIM_ADDR
 * returns 0 if completed, non-zero if not completed
 * NOTE: if adding, but delete already scheduled (and not yet
 *      sent out), simply remove from queue.  Same for deleting
 *      an address already scheduled for add.  If a duplicate
 *      operation is found, ignore the new one.
 */
static uint32_t
sctp_asconf_queue_add_sa(struct sctp_tcb *stcb, struct sockaddr *sa,
    uint16_t type)
{
        struct sctp_asconf_addr *aa, *aa_next;

        /* see if peer supports ASCONF */
        if (stcb->asoc.peer_supports_asconf == 0) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_queue_add_sa: peer doesn't support ASCONF\n");
                }
#endif /* SCTP_DEBUG */
                return (-1);
        }

        /* make sure the request isn't already in the queue */
        for (aa = TAILQ_FIRST(&stcb->asoc.asconf_queue); aa != NULL;
            aa = aa_next) {
                aa_next = TAILQ_NEXT(aa, next);
                /* address match? */
                if (sctp_asconf_addr_match(aa, sa) == 0)
                        continue;
                /* is the request already in queue (sent or not) */
                if (aa->ap.aph.ph.param_type == type) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("asconf_queue_add_sa: request already exists\n");
                        }
#endif /* SCTP_DEBUG */
                        return (-1);
                }

                /* is the negative request already in queue, and not sent */
                if (aa->sent == 1)
                        continue;
                if (type == SCTP_ADD_IP_ADDRESS &&
                    aa->ap.aph.ph.param_type == SCTP_DEL_IP_ADDRESS) {
                        /* add requested, delete already queued */

                        /* delete the existing entry in the queue */
                        TAILQ_REMOVE(&stcb->asoc.asconf_queue, aa, next);
                        /* free the entry */
                        free(aa, M_PCB);
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("asconf_queue_add_sa: removing queued delete request\n");
                        }
#endif /* SCTP_DEBUG */
                        return (-1);
                } else if (type == SCTP_DEL_IP_ADDRESS &&
                           aa->ap.aph.ph.param_type == SCTP_ADD_IP_ADDRESS) {
                        /* delete requested, add already queued */

                        /* delete the existing entry in the queue */
                        TAILQ_REMOVE(&stcb->asoc.asconf_queue, aa, next);
                        /* take the entry off the appropriate list */
                        sctp_asconf_addr_mgmt_ack(stcb, aa->ifa, type, 1);
                        /* free the entry */
                        free(aa, M_PCB);
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("asconf_queue_add_sa: removing queued add request\n");
                        }
#endif /* SCTP_DEBUG */
                        return (-1);
                }
        } /* for each aa */

        /* adding new request to the queue */
        aa = malloc(sizeof(*aa), M_PCB, M_NOWAIT);
        if (aa == NULL) {
                /* didn't get memory */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_queue_add_sa: failed to get memory!\n");
                }
#endif /* SCTP_DEBUG */
                return (-1);
        }
        /* fill in asconf address parameter fields */
        /* top level elements are "networked" during send */
        aa->ap.aph.ph.param_type = type;
        aa->ifa = sctp_find_ifa_by_addr(sa);
        /* correlation_id filled in during send routine later... */
        if (sa->sa_family == AF_INET6) {
                /* IPv6 address */
                struct sockaddr_in6 *sin6;

                sin6 = (struct sockaddr_in6 *)sa;
                aa->ap.addrp.ph.param_type = SCTP_IPV6_ADDRESS;
                aa->ap.addrp.ph.param_length = (sizeof(struct sctp_ipv6addr_param));
                aa->ap.aph.ph.param_length = sizeof(struct sctp_asconf_paramhdr) + sizeof(struct sctp_ipv6addr_param);
                memcpy(&aa->ap.addrp.addr, &sin6->sin6_addr,
                    sizeof(struct in6_addr));
        } else if (sa->sa_family == AF_INET) {
                /* IPv4 address */
                struct sockaddr_in *sin = (struct sockaddr_in *)sa;
                aa->ap.addrp.ph.param_type = SCTP_IPV4_ADDRESS;
                aa->ap.addrp.ph.param_length = (sizeof(struct sctp_ipv4addr_param));
                aa->ap.aph.ph.param_length = sizeof(struct sctp_asconf_paramhdr) + sizeof(struct sctp_ipv4addr_param);
                memcpy(&aa->ap.addrp.addr, &sin->sin_addr,
                    sizeof(struct in_addr));
        } else {
                /* invalid family! */
                return (-1);
        }
        aa->sent = 0;                   /* clear sent flag */

        /*
         * if we are deleting an address it should go out last
         * otherwise, add it to front of the pending queue
         */
        if (type == SCTP_ADD_IP_ADDRESS) {
                /* add goes to the front of the queue */
                TAILQ_INSERT_HEAD(&stcb->asoc.asconf_queue, aa, next);
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_queue_add_sa: appended asconf ADD_IP_ADDRESS\n");
                }
#endif /* SCTP_DEBUG */
        } else {
                /* delete and set primary goes to the back of the queue */
                TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa, next);
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        if (type == SCTP_DEL_IP_ADDRESS) {
                                printf("asconf_queue_add_sa: inserted asconf DEL_IP_ADDRESS\n");
                        } else {
                                printf("asconf_queue_add_sa: inserted asconf SET_PRIM_ADDR\n");
                        }
                }
#endif /* SCTP_DEBUG */
        }

        return (0);
}

/*
 * find a specific asconf param on our "sent" queue
 */
static struct sctp_asconf_addr *
sctp_asconf_find_param(struct sctp_tcb *stcb, uint32_t correlation_id)
{
        struct sctp_asconf_addr *aa;

        TAILQ_FOREACH(aa, &stcb->asoc.asconf_queue, next) {
                if (aa->ap.aph.correlation_id == correlation_id &&
                    aa->sent == 1) {
                        /* found it */
                        return (aa);
                }
        }
        /* didn't find it */
        return (NULL);
}

/*
 * process an SCTP_ERROR_CAUSE_IND for a ASCONF-ACK parameter
 * and do notifications based on the error response
 */
static void
sctp_asconf_process_error(struct sctp_tcb *stcb,
    struct sctp_asconf_paramhdr *aph)
{
        struct sctp_error_cause *eh;
        struct sctp_paramhdr *ph;
        uint16_t param_type;
        uint16_t error_code;

        eh = (struct sctp_error_cause *)(aph + 1);
        ph = (struct sctp_paramhdr *)(eh + 1);
        /* validate lengths */
        if (htons(eh->length) + sizeof(struct sctp_error_cause) >
            htons(aph->ph.param_length)) {
                /* invalid error cause length */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_process_error: cause element too long\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }
        if (htons(ph->param_length) + sizeof(struct sctp_paramhdr) >
            htons(eh->length)) {
                /* invalid included TLV length */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("asconf_process_error: included TLV too long\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }

        /* which error code ? */
        error_code = ntohs(eh->code);
        param_type = ntohs(aph->ph.param_type);
        /* FIX: this should go back up the REMOTE_ERROR ULP notify */
        switch (error_code) {
        case SCTP_ERROR_RESOURCE_SHORTAGE:
                /* we allow ourselves to "try again" for this error */
                break;
        default:
                /* peer can't handle it... */
                switch (param_type) {
                case SCTP_ADD_IP_ADDRESS:
                case SCTP_DEL_IP_ADDRESS:
                        stcb->asoc.peer_supports_asconf = 0;
                        break;
                case SCTP_SET_PRIM_ADDR:
                        stcb->asoc.peer_supports_asconf_setprim = 0;
                        break;
                default:
                        break;
                }
        }
}

/*
 * process an asconf queue param
 * aparam: parameter to process, will be removed from the queue
 * flag: 1=success, 0=failure
 */
static void
sctp_asconf_process_param_ack(struct sctp_tcb *stcb,
    struct sctp_asconf_addr *aparam, uint32_t flag)
{
        uint16_t param_type;

        /* process this param */
        param_type = aparam->ap.aph.ph.param_type;
#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                printf("process_param_ack: handling asconf parameter type=%xh\n", param_type);
        }
#endif /* SCTP_DEBUG */
        switch (param_type) {
        case SCTP_ADD_IP_ADDRESS:
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_param_ack: added IP address\n");
                }
#endif /* SCTP_DEBUG */
                sctp_asconf_addr_mgmt_ack(stcb, aparam->ifa, param_type, flag);
                break;
        case SCTP_DEL_IP_ADDRESS:
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_param_ack: deleted IP address\n");
                }
#endif /* SCTP_DEBUG */
                /* nothing really to do... lists already updated */
                break;
        case SCTP_SET_PRIM_ADDR:
                /* nothing to do... peer may start using this addr */
                if (flag == 0)
                        stcb->asoc.peer_supports_asconf_setprim = 0;
                break;
        default:
                /* should NEVER happen */
                break;
        } /* switch */

        /* remove the param and free it */
        TAILQ_REMOVE(&stcb->asoc.asconf_queue, aparam, next);
        free(aparam, M_PCB);
}

/*
 * cleanup from a bad asconf ack parameter
 */
static void
sctp_asconf_ack_clear(struct sctp_tcb *stcb)
{
        /* assume peer doesn't really know how to do asconfs */
        stcb->asoc.peer_supports_asconf = 0;
        stcb->asoc.peer_supports_asconf_setprim = 0;
        /* XXX we could free the pending queue here */
}

void
sctp_handle_asconf_ack(struct mbuf *m, int offset,
    struct sctp_asconf_ack_chunk *cp, struct sctp_tcb *stcb,
    struct sctp_nets *net)
{
        struct sctp_association *asoc;
        uint32_t serial_num;
        uint16_t ack_length;
        struct sctp_asconf_paramhdr *aph;
        struct sctp_asconf_addr *aa, *aa_next;
        uint32_t last_error_id = 0;             /* last error correlation id */
        uint32_t id;
        struct sctp_asconf_addr *ap;
        /* asconf param buffer */
        static u_int8_t aparam_buf[DEFAULT_PARAM_BUFFER];

        /* verify minimum length */
        if (ntohs(cp->ch.chunk_length) < sizeof(struct sctp_asconf_ack_chunk)) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("handle_asconf_ack: chunk too small = %xh\n",
                               ntohs(cp->ch.chunk_length));
                }
#endif /* SCTP_DEBUG */
                return;
        }

        asoc = &stcb->asoc;
        serial_num = ntohl(cp->serial_number);

        /*
         * NOTE: we may want to handle this differently- currently, we
         * will abort when we get an ack for the expected serial number + 1
         * (eg. we didn't send it), process an ack normally if it is the
         * expected serial number, and re-send the previous ack for *ALL*
         * other serial numbers
         */

        /*
         * if the serial number is the next expected, but I didn't send it,
         * abort the asoc, since someone probably just hijacked us...
         */
        if (serial_num == (asoc->asconf_seq_out + 1)) {
                sctp_abort_an_association(stcb->sctp_ep, stcb,
                    SCTP_ERROR_ILLEGAL_ASCONF_ACK, NULL);
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("handle_asconf_ack: got unexpected next serial number! Aborting asoc!\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }

        if (serial_num != asoc->asconf_seq_out) {
                /* got a duplicate/unexpected ASCONF-ACK */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("handle_asconf_ack: got duplicate/unexpected serial number = %xh (expected = %xh)\n", serial_num, asoc->asconf_seq_out);
                }
#endif /* SCTP_DEBUG */
                return;
        }
        /* stop our timer */
        sctp_timer_stop(SCTP_TIMER_TYPE_ASCONF, stcb->sctp_ep, stcb, net);

        /* process the ASCONF-ACK contents */
        ack_length = ntohs(cp->ch.chunk_length) -
            sizeof(struct sctp_asconf_ack_chunk);
        offset += sizeof(struct sctp_asconf_ack_chunk);
        /* process through all parameters */
        while (ack_length >= sizeof(struct sctp_asconf_paramhdr)) {
                unsigned int param_length, param_type;

                /* get pointer to next asconf parameter */
                aph = (struct sctp_asconf_paramhdr *)sctp_m_getptr(m, offset,
                    sizeof(struct sctp_asconf_paramhdr), aparam_buf);
                if (aph == NULL) {
                        /* can't get an asconf paramhdr */
                        sctp_asconf_ack_clear(stcb);
                        return;
                }
                param_type = ntohs(aph->ph.param_type);
                param_length = ntohs(aph->ph.param_length);
                if (param_length > ack_length) {
                        sctp_asconf_ack_clear(stcb);
                        return;
                }
                if (param_length < sizeof(struct sctp_paramhdr)) {
                        sctp_asconf_ack_clear(stcb);
                        return;
                }

                /* get the complete parameter... */
                if (param_length > sizeof(aparam_buf)) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("param length (%u) larger than buffer size!\n", param_length);
                        }
#endif /* SCTP_DEBUG */
                        sctp_asconf_ack_clear(stcb);
                        return;
                }
                aph = (struct sctp_asconf_paramhdr *)sctp_m_getptr(m, offset, param_length, aparam_buf);
                if (aph == NULL) {
                        sctp_asconf_ack_clear(stcb);
                        return;
                }
                /* correlation_id is transparent to peer, no ntohl needed */
                id = aph->correlation_id;

                switch (param_type) {
                case SCTP_ERROR_CAUSE_IND:
                        last_error_id = id;
                        /* find the corresponding asconf param in our queue */
                        ap = sctp_asconf_find_param(stcb, id);
                        if (ap == NULL) {
                                /* hmm... can't find this in our queue! */
                                break;
                        }
                        /* process the parameter, failed flag */
                        sctp_asconf_process_param_ack(stcb, ap, 0);
                        /* process the error response */
                        sctp_asconf_process_error(stcb, aph);
                        break;
                case SCTP_SUCCESS_REPORT:
                        /* find the corresponding asconf param in our queue */
                        ap = sctp_asconf_find_param(stcb, id);
                        if (ap == NULL) {
                                /* hmm... can't find this in our queue! */
                                break;
                        }
                        /* process the parameter, success flag */
                        sctp_asconf_process_param_ack(stcb, ap, 1);
                        break;
                default:
                        break;
                } /* switch */

                /* update remaining ASCONF-ACK message length to process */
                ack_length -= SCTP_SIZE32(param_length);
                if (ack_length <= 0) {
                        /* no more data in the mbuf chain */
                        break;
                }
                offset += SCTP_SIZE32(param_length);
        } /* while */

        /*
         * if there are any "sent" params still on the queue, these are
         * implicitly "success", or "failed" (if we got an error back)
         * ... so process these appropriately
         *
         * we assume that the correlation_id's are monotonically increasing
         * beginning from 1 and that we don't have *that* many outstanding
         * at any given time
         */
        if (last_error_id == 0)
                last_error_id--;        /* set to "max" value */
        for (aa = TAILQ_FIRST(&stcb->asoc.asconf_queue); aa != NULL;
            aa = aa_next) {
                aa_next = TAILQ_NEXT(aa, next);
                if (aa->sent == 1) {
                        /*
                         * implicitly successful or failed
                         * if correlation_id < last_error_id, then success
                         * else, failure
                         */
                        if (aa->ap.aph.correlation_id < last_error_id)
                                sctp_asconf_process_param_ack(stcb, aa,
                                    SCTP_SUCCESS_REPORT);
                        else
                                sctp_asconf_process_param_ack(stcb, aa,
                                    SCTP_ERROR_CAUSE_IND);
                } else {
                        /*
                         * since we always process in order (FIFO queue)
                         * if we reach one that hasn't been sent, the
                         * rest should not have been sent either.
                         * so, we're done...
                         */
                        break;
                }
        }

        /* update the next sequence number to use */
        asoc->asconf_seq_out++;
        /* remove the old ASCONF on our outbound queue */
        sctp_toss_old_asconf(stcb);
        /* clear the sent flag to allow new ASCONFs */
        asoc->asconf_sent = 0;
        if (!TAILQ_EMPTY(&stcb->asoc.asconf_queue)) {
                /* we have more params, so restart our timer */
                sctp_timer_start(SCTP_TIMER_TYPE_ASCONF, stcb->sctp_ep,
                    stcb, net);
        }
}

/* is this an interface that we care about at all? */
static uint32_t
sctp_is_desired_interface_type(struct ifaddr *ifa)
{
        int result;

        /* check the interface type to see if it's one we care about */
        switch (ifa->ifa_ifp->if_type) {
        case IFT_ETHER:
        case IFT_ISO88023:
        case IFT_ISO88025:
        case IFT_STARLAN:
        case IFT_P10:
        case IFT_P80:
        case IFT_HY:
        case IFT_FDDI:
        case IFT_PPP:
        case IFT_XETHER:
        case IFT_SLIP:
        case IFT_GIF:
        case IFT_IPSEC:
                result = 1;
                break;
        default:
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("ignoring interface type = %u\n",
                               ifa->ifa_ifp->if_type);
                }
#endif /* SCTP_DEBUG */
                result = 0;
        } /* end switch */

        return (result);
}

static uint32_t
sctp_is_scopeid_in_nets(struct sctp_tcb *stcb, struct sockaddr *sa)
{
        struct sockaddr_in6 *sin6;
        const struct sockaddr_in6 *net6;
        struct sctp_nets *net;

        if (sa->sa_family != AF_INET6) {
                /* wrong family */
                return (0);
        }

        sin6 = (struct sockaddr_in6 *)sa;
        if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) == 0) {
                /* not link local address */
                return (0);
        }
        /* hunt through our destination nets list for this scope_id */
        TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
                if ((rtcache_getdst(&net->ro))->sa_family !=
                    AF_INET6)
                        continue;
                net6 = (const struct sockaddr_in6 *)rtcache_getdst(&net->ro);
                if (IN6_IS_ADDR_LINKLOCAL(&net6->sin6_addr) == 0)
                        continue;
                if (sctp_is_same_scope(sin6, net6)) {
                        /* found one */
                        return (1);
                }
        }
        /* didn't find one */
        return (0);
}

/*
 * address management functions
 */
static void
sctp_addr_mgmt_assoc(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct ifaddr *ifa, uint16_t type)
{
        int status;
#ifdef SCTP_DEBUG
        char buf[128];  /* for address in string format */
#endif /* SCTP_DEBUG */

        if ((inp->sctp_flags & SCTP_PCB_FLAGS_BOUNDALL) == 0 &&
            (inp->sctp_flags & SCTP_PCB_FLAGS_DO_ASCONF) == 0) {
                /* subset bound, no ASCONF allowed case, so ignore */
                return;
        }

        /*
         * note: we know this is not the subset bound, no ASCONF case
         *      eg. this is boundall or subset bound w/ASCONF allowed
         */

        /* first, make sure it's a good address family */
        if (ifa->ifa_addr->sa_family != AF_INET6 &&
            ifa->ifa_addr->sa_family != AF_INET) {
                return;
        }

        /* make sure we're "allowed" to add this type of addr */
        if (ifa->ifa_addr->sa_family == AF_INET6) {
                struct in6_ifaddr *ifa6;

                /* invalid if we're not a v6 endpoint */
                if ((inp->sctp_flags & SCTP_PCB_FLAGS_BOUND_V6) == 0)
                        return;
                /* is the v6 addr really valid ? */
                ifa6 = (struct in6_ifaddr *)ifa;
                if (IFA6_IS_DEPRECATED(ifa6) ||
                    (ifa6->ia6_flags &
                     (IN6_IFF_DETACHED | IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) {
                        /* can't use an invalid address */
                        return;
                }
        }

        /* put this address on the "pending/do not use yet" list */
        /*
         * Note: we do this primarily for the subset bind case
         * We don't have scoping flags at the EP level, so we must
         * add link local/site local addresses to the EP, then need
         * to "negate" them here.  Recall that this routine is only
         * called for the subset bound w/ASCONF allowed case.
         */

        /*
         * do a scope_id check against any link local addresses
         * in the destination nets list to see if we should put
         * this local address on the pending list or not
         * eg. don't put on the list if we have a link local
         * destination with the same scope_id
         */
        if (type == SCTP_ADD_IP_ADDRESS) {
                if (sctp_is_scopeid_in_nets(stcb, ifa->ifa_addr) == 0) {
                        sctp_add_local_addr_assoc(stcb, ifa);
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("addr_mgmt_assoc: added to pending list ");
                                sctp_print_address(ifa->ifa_addr);
                        }
#endif /* SCTP_DEBUG */
                }
        }
        /*
         * check address scope
         * if address is out of scope, don't queue anything...
         * note: this would leave the address on both inp and asoc lists
         */
        if (ifa->ifa_addr->sa_family == AF_INET6) {
#ifdef SCTP_DEBUG
                char ip6buf[INET6_ADDRSTRLEN];
#endif /* SCTP_DEBUG */
                struct sockaddr_in6 *sin6;

                sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
#ifdef SCTP_DEBUG
                strlcpy(buf, IN6_PRINT(ip6buf, &sin6->sin6_addr), sizeof(buf));
#endif /* SCTP_DEBUG */
                if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
                        /* we skip unspecified addresses */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("addr_mgmt_assoc: unspecified IPv6 addr\n");
                        }
#endif /* SCTP_DEBUG */
                        return;
                }
                if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
                        if (stcb->asoc.local_scope == 0) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                        printf("addr_mgmt_assoc: skipping link local IPv6 addr: %s\n", buf);
                                }
#endif /* SCTP_DEBUG */
                                return;
                        }
                        /* is it the right link local scope? */
                        if (sctp_is_scopeid_in_nets(stcb, ifa->ifa_addr) == 0) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                        printf("addr_mgmt_assoc: skipping link local IPv6 addr: %s, wrong scope_id\n", buf);
                                }
#endif /* SCTP_DEBUG */
                                return;
                        }
                }
                if (stcb->asoc.site_scope == 0 &&
                    IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr)) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("addr_mgmt_assoc: skipping site local IPv6 addr: %s\n", buf);
                        }
#endif /* SCTP_DEBUG */
                        return;
                }
        } else if (ifa->ifa_addr->sa_family == AF_INET) {
                struct sockaddr_in *sin;
                struct in6pcb *inp6;

                inp6 = (struct in6pcb *)&inp->ip_inp.inp;
                /* invalid if we are a v6 only endpoint */
                if ((inp->sctp_flags & SCTP_PCB_FLAGS_BOUND_V6) &&
                    (inp6->in6p_flags & IN6P_IPV6_V6ONLY)
                        )
                        return;

                sin = (struct sockaddr_in *)ifa->ifa_addr;
#ifdef SCTP_DEBUG
                strlcpy(buf, inet_ntoa(sin->sin_addr), sizeof(buf));
#endif /* SCTP_DEBUG */
                if (sin->sin_addr.s_addr == 0) {
                        /* we skip unspecified addresses */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("addr_mgmt_assoc: unspecified IPv4 addr\n");
                        }
#endif /* SCTP_DEBUG */
                        return;
                }
                if (stcb->asoc.ipv4_local_scope == 0 &&
                    IN4_ISPRIVATE_ADDRESS(&sin->sin_addr)) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("addr_mgmt_assoc: skipping private IPv4 addr: %s\n", buf);
                        }
#endif /* SCTP_DEBUG */
                        return;
                }
        } else {
                /* else, not AF_INET or AF_INET6, so skip */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("addr_mgmt_assoc: not AF_INET or AF_INET6\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }

        /* queue an asconf for this address add/delete */
        if (inp->sctp_flags & SCTP_PCB_FLAGS_DO_ASCONF) {
                /* does the peer do asconf? */
                if (stcb->asoc.peer_supports_asconf) {
                        /* queue an asconf for this addr */
                        status = sctp_asconf_queue_add(stcb, ifa, type);
                        /*
                         * if queued ok, and in correct state, set the
                         * ASCONF timer
                         * if in non-open state, we will set this timer
                         * when the state does go open and do all the
                         * asconf's
                         */
                        if (status == 0 &&
                            SCTP_GET_STATE(&stcb->asoc) == SCTP_STATE_OPEN) {
                                sctp_timer_start(SCTP_TIMER_TYPE_ASCONF, inp,
                                    stcb, stcb->asoc.primary_destination);
                        }
                }
        } else {
                /* this is the boundall, no ASCONF case */
#if 0 /* assume kernel will delete this very shortly; add done above */
                if (type == SCTP_DEL_IP_ADDRESS) {
                        /* if deleting, add this addr to the do not use list */
                        sctp_add_local_addr_assoc(stcb, ifa);
                }
#endif
        }
}

static void
sctp_addr_mgmt_ep(struct sctp_inpcb *inp, struct ifaddr *ifa, uint16_t type)
{
        struct sctp_tcb *stcb;
        int s;

        SCTP_INP_WLOCK(inp);
        /* make sure we're "allowed" to add this type of addr */
        if (ifa->ifa_addr->sa_family == AF_INET6) {
                struct in6_ifaddr *ifa6;

                /* invalid if we're not a v6 endpoint */
                if ((inp->sctp_flags & SCTP_PCB_FLAGS_BOUND_V6) == 0) {
                        SCTP_INP_WUNLOCK(inp);
                        return;
                }
                /* is the v6 addr really valid ? */
                ifa6 = (struct in6_ifaddr *)ifa;
                if (IFA6_IS_DEPRECATED(ifa6) ||
                    (ifa6->ia6_flags &
                     (IN6_IFF_DETACHED | IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) {
                        /* can't use an invalid address */
                        SCTP_INP_WUNLOCK(inp);
                        return;
                }
        } else if (ifa->ifa_addr->sa_family == AF_INET) {
                /* invalid if we are a v6 only endpoint */
                struct in6pcb *inp6;
                inp6 = (struct in6pcb *)&inp->ip_inp.inp;

                if ((inp->sctp_flags & SCTP_PCB_FLAGS_BOUND_V6) &&
                    (inp6->in6p_flags & IN6P_IPV6_V6ONLY)
                        ) {
                        SCTP_INP_WUNLOCK(inp);
                        return;
                }
        } else {
                /* invalid address family */
                SCTP_INP_WUNLOCK(inp);
                return;
        }
        /* is this endpoint subset bound ? */
        if ((inp->sctp_flags & SCTP_PCB_FLAGS_BOUNDALL) == 0) {
                /* subset bound endpoint */
                if ((inp->sctp_flags & SCTP_PCB_FLAGS_DO_ASCONF) == 0) {
                        /*
                         * subset bound, but ASCONFs not allowed...
                         * if adding, nothing to do, since not allowed
                         * if deleting, remove address from endpoint
                         *      peer will have to "timeout" this addr
                         */
                        if (type == SCTP_DEL_IP_ADDRESS) {
                                sctp_del_local_addr_ep(inp, ifa);
                        }
                        /* no asconfs to queue for this inp... */
                        SCTP_INP_WUNLOCK(inp);
                        return;
                } else {
                        /*
                         * subset bound, ASCONFs allowed...
                         * if adding, add address to endpoint list
                         * if deleting, remove address from endpoint
                         */
                        if (type == SCTP_ADD_IP_ADDRESS) {
                                sctp_add_local_addr_ep(inp, ifa);
                        } else {
                                sctp_del_local_addr_ep(inp, ifa);
                        }
                        /* drop through and notify all asocs */
                }
        }

        s = splsoftnet();
        /* process for all associations for this endpoint */
        LIST_FOREACH(stcb, &inp->sctp_asoc_list, sctp_tcblist) {
                SCTP_TCB_LOCK(stcb);
                sctp_addr_mgmt_assoc(inp, stcb, ifa, type);
                SCTP_TCB_UNLOCK(stcb);
        } /* for each stcb */
        splx(s);
        SCTP_INP_WUNLOCK(inp);
}

/*
 * restrict the use of this address
 */
static void
sctp_addr_mgmt_restrict_ep(struct sctp_inpcb *inp, struct ifaddr *ifa)
{
        struct sctp_tcb *stcb;
        int s;

        /* is this endpoint bound to all? */
        if ((inp->sctp_flags & SCTP_PCB_FLAGS_BOUNDALL) == 0) {
                /*
                 * Nothing to do for subset bound case.
                 * Allow sctp_bindx() to manage the address lists
                 */
                return;
        }

        s = splsoftnet();
        SCTP_INP_RLOCK(inp);
        /* process for all associations for this endpoint */
        LIST_FOREACH(stcb, &inp->sctp_asoc_list, sctp_tcblist) {
                /* put this address on the "pending/do not use yet" list */
                SCTP_TCB_LOCK(stcb);
                sctp_add_local_addr_assoc(stcb, ifa);
                SCTP_TCB_UNLOCK(stcb);
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("restrict_ep: added addr to unusable list\n");
                }
#endif /* SCTP_DEBUG */
        } /* for each stcb */
        splx(s);
        SCTP_INP_RUNLOCK(inp);
}

/*
 * this is only called for kernel initiated address changes
 * eg. it will check the PCB_FLAGS_AUTO_ASCONF flag
 */
static void
sctp_addr_mgmt(struct ifaddr *ifa, uint16_t type) {
        struct sockaddr *sa;
        struct sctp_inpcb *inp;

        /* make sure we care about this interface... */
        if (!sctp_is_desired_interface_type(ifa)) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("sctp_addr_mgmt: ignoring this interface\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }

        sa = ifa->ifa_addr;
        if (sa->sa_family != AF_INET && sa->sa_family != AF_INET6)
                return;

#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                if (type == SCTP_ADD_IP_ADDRESS)
                        printf("sctp_addr_mgmt: kernel adds ");
                else
                        printf("sctp_addr_mgmt: kernel deletes ");
                sctp_print_address(sa);
        }
#endif /* SCTP_DEBUG */

        /* go through all our PCB's */
        LIST_FOREACH(inp, &sctppcbinfo.listhead, sctp_list) {
                if (inp->sctp_flags & SCTP_PCB_FLAGS_AUTO_ASCONF) {
                        sctp_addr_mgmt_ep(inp, ifa, type);
                } else {
                        /* this address is going away anyways... */
                        if (type == SCTP_DEL_IP_ADDRESS)
                                return;
                        /* (temporarily) restrict this address */
                        sctp_addr_mgmt_restrict_ep(inp, ifa);
                }
                /* else, not allowing automatic asconf's, so ignore */
        } /* for each inp */
}

/*
 * add/delete IP address requests from kernel (via routing change)
 * assumed that the address is non-broadcast, non-multicast
 * all addresses are passed from any type of interface-- need to filter
 * duplicate addresses may get requested
 */

void
sctp_add_ip_address(struct ifaddr *ifa)
{
        sctp_addr_mgmt(ifa, SCTP_ADD_IP_ADDRESS);
}

void
sctp_delete_ip_address(struct ifaddr *ifa)
{
        struct sctp_inpcb *inp;

        /* process the delete */
        sctp_addr_mgmt(ifa, SCTP_DEL_IP_ADDRESS);

        /*
         * need to remove this ifaddr from any cached routes
         * and also any from any assoc "restricted/pending" lists
         */
        /* make sure we care about this interface... */
        if (!sctp_is_desired_interface_type(ifa)) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("sctp_delete_ip_address: ignoring this interface\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }

        /* go through all our PCB's */
        SCTP_INP_INFO_RLOCK();
        LIST_FOREACH(inp, &sctppcbinfo.listhead, sctp_list) {
                struct sctp_tcb *stcb;
                struct sctp_laddr *laddr, *laddr_next;

                /* process for all associations for this endpoint */
                SCTP_INP_RLOCK(inp);
                LIST_FOREACH(stcb, &inp->sctp_asoc_list, sctp_tcblist) {
                        struct sctp_nets *net;

                        /* process through the nets list */
                        TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
                                rtcache_free(&net->ro); /* XXX - was clear */
                        } /* for each net */
                        /* process through the asoc "pending" list */
                        laddr = LIST_FIRST(&stcb->asoc.sctp_local_addr_list);
                        while (laddr != NULL) {
                                laddr_next = LIST_NEXT(laddr, sctp_nxt_addr);
                                /* remove if in use */
                                if (laddr->ifa == ifa) {
                                        sctp_remove_laddr(laddr);
                                }
                                laddr = laddr_next;
                        } /* while */
                } /* for each stcb */
                /* process through the inp bound addr list */
                laddr = LIST_FIRST(&inp->sctp_addr_list);
                while (laddr != NULL) {
                        laddr_next = LIST_NEXT(laddr, sctp_nxt_addr);
                        /* remove if in use */
                        if (laddr->ifa == ifa) {
                                sctp_remove_laddr(laddr);
                        }
                        laddr = laddr_next;
                } /* while */
                SCTP_INP_RUNLOCK(inp);
        } /* for each inp */
        SCTP_INP_INFO_RUNLOCK();
}

/*
 * sa is the sockaddr to ask the peer to set primary to
 * returns: 0 = completed, -1 = error
 */
int32_t
sctp_set_primary_ip_address_sa(struct sctp_tcb *stcb, struct sockaddr *sa)
{
        /* NOTE: we currently don't check the validity of the address! */

        /* queue an ASCONF:SET_PRIM_ADDR to be sent */
        if (!sctp_asconf_queue_add_sa(stcb, sa, SCTP_SET_PRIM_ADDR)) {
                /* set primary queuing succeeded */
                if (SCTP_GET_STATE(&stcb->asoc) == SCTP_STATE_OPEN) {
                        sctp_timer_start(SCTP_TIMER_TYPE_ASCONF,
                            stcb->sctp_ep, stcb,
                            stcb->asoc.primary_destination);
                }
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("set_primary_ip_address_sa: queued on tcb=%p, ",
                            stcb);
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
        } else {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("set_primary_ip_address_sa: failed to add to queue on tcb=%p, ",
                            stcb);
                        sctp_print_address(sa);
                }
#endif /* SCTP_DEBUG */
                return (-1);
        }
        return (0);
}

void
sctp_set_primary_ip_address(struct ifaddr *ifa)
{
        struct sctp_inpcb *inp;

        /* make sure we care about this interface... */
        if (!sctp_is_desired_interface_type(ifa)) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("set_primary_ip_address: ignoring this interface\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }

        /* go through all our PCB's */
        LIST_FOREACH(inp, &sctppcbinfo.listhead, sctp_list) {
                struct sctp_tcb *stcb;

                /* process for all associations for this endpoint */
                LIST_FOREACH(stcb, &inp->sctp_asoc_list, sctp_tcblist) {
                        /* queue an ASCONF:SET_PRIM_ADDR to be sent */
                        if (!sctp_asconf_queue_add(stcb, ifa,
                            SCTP_SET_PRIM_ADDR)) {
                                /* set primary queuing succeeded */
                                if (SCTP_GET_STATE(&stcb->asoc) ==
                                    SCTP_STATE_OPEN) {
                                        sctp_timer_start(SCTP_TIMER_TYPE_ASCONF,
                                            stcb->sctp_ep, stcb,
                                            stcb->asoc.primary_destination);
                                }
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                        printf("set_primary_ip_address: queued on stcb=%p, ",
                                            stcb);
                                        sctp_print_address(ifa->ifa_addr);
                                }
#endif /* SCTP_DEBUG */
                        } else {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                        printf("set_primary_ip_address: failed to add to queue, ");
                                        sctp_print_address(ifa->ifa_addr);
                                }
#endif /* SCTP_DEBUG */
                        }
                } /* for each stcb */
        } /* for each inp */
}

static struct sockaddr *
sctp_find_valid_localaddr(struct sctp_tcb *stcb)
{
        struct ifnet *ifn;
        struct ifaddr *ifa;
        int s;

        s = pserialize_read_enter();
        IFNET_READER_FOREACH(ifn) {
                if (stcb->asoc.loopback_scope == 0 && ifn->if_type == IFT_LOOP) {
                        /* Skip if loopback_scope not set */
                        continue;
                }
                IFADDR_READER_FOREACH(ifa, ifn) {
                        if (ifa->ifa_addr->sa_family == AF_INET &&
                            stcb->asoc.ipv4_addr_legal) {
                                struct sockaddr_in *sin;

                                sin = (struct sockaddr_in *)ifa->ifa_addr;
                                if (sin->sin_addr.s_addr == 0) {
                                        /* skip unspecified addresses */
                                        continue;
                                }
                                if (stcb->asoc.ipv4_local_scope == 0 &&
                                    IN4_ISPRIVATE_ADDRESS(&sin->sin_addr))
                                        continue;

                                if (sctp_is_addr_restricted(stcb,
                                    ifa->ifa_addr))
                                        continue;
                                pserialize_read_exit(s);

                                /* found a valid local v4 address to use */
                                return (ifa->ifa_addr);
                        } else if (ifa->ifa_addr->sa_family == AF_INET6 &&
                            stcb->asoc.ipv6_addr_legal) {
                                struct sockaddr_in6 *sin6;
                                struct in6_ifaddr *ifa6;

                                ifa6 = (struct in6_ifaddr *)ifa;
                                if (IFA6_IS_DEPRECATED(ifa6) ||
                                    (ifa6->ia6_flags & (IN6_IFF_DETACHED |
                                     IN6_IFF_ANYCAST | IN6_IFF_NOTREADY)))
                                        continue;

                                sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
                                if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
                                        /* we skip unspecified addresses */
                                        continue;
                                }
                                if (stcb->asoc.local_scope == 0 &&
                                    IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
                                        continue;
                                if (stcb->asoc.site_scope == 0 &&
                                    IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
                                        continue;

                                pserialize_read_exit(s);
                                /* found a valid local v6 address to use */
                                return (ifa->ifa_addr);
                        }
                }
        }
        pserialize_read_exit(s);

        /* no valid addresses found */
        return (NULL);
}

static struct sockaddr *
sctp_find_valid_localaddr_ep(struct sctp_tcb *stcb)
{
        struct sctp_laddr *laddr;

        LIST_FOREACH(laddr, &stcb->sctp_ep->sctp_addr_list, sctp_nxt_addr) {
                if (laddr->ifa == NULL) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("find_valid_localaddr_ep: laddr error\n");
                        }
#endif /* SCTP_DEBUG */
                        continue;
                }
                if (laddr->ifa->ifa_addr == NULL) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("find_valid_localaddr_ep: laddr->ifa error\n");
                        }
#endif /* SCTP_DEBUG */
                        continue;
                }
                /* is the address restricted ? */
                if (sctp_is_addr_restricted(stcb, laddr->ifa->ifa_addr))
                        continue;

                /* found a valid local address to use */
                return (laddr->ifa->ifa_addr);
        }
        /* no valid addresses found */
        return (NULL);
}

/*
 * builds an ASCONF chunk from queued ASCONF params
 * returns NULL on error (no mbuf, no ASCONF params queued, etc)
 */
struct mbuf *
sctp_compose_asconf(struct sctp_tcb *stcb)
{
        struct mbuf *m_asconf, *m_asconf_chk;
        struct sctp_asconf_addr *aa;
        struct sctp_asconf_chunk *acp;
        struct sctp_asconf_paramhdr *aph;
        struct sctp_asconf_addr_param *aap;
        uint32_t p_length;
        uint32_t correlation_id = 1;            /* 0 is reserved... */
        vaddr_t ptr, lookup_ptr;
        uint8_t lookup_used = 0;

        /* are there any asconf params to send? */
        if (TAILQ_EMPTY(&stcb->asoc.asconf_queue)) {
                return (NULL);
        }

        /*
         * get a chunk header mbuf and a cluster for the asconf params
         * since it's simpler to fill in the asconf chunk header lookup
         * address on the fly
         */
        m_asconf_chk = NULL;
        MGETHDR(m_asconf_chk, M_DONTWAIT, MT_DATA);
        if (m_asconf_chk == NULL) {
                /* no mbuf's */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1)
                        printf("compose_asconf: couldn't get chunk mbuf!\n");
#endif /* SCTP_DEBUG */
                return (NULL);
        }
        m_asconf = NULL;
        MGETHDR(m_asconf, M_DONTWAIT, MT_HEADER);
        if (m_asconf == NULL) {
                /* no mbuf's */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1)
                        printf("compose_asconf: couldn't get mbuf!\n");
#endif /* SCTP_DEBUG */
                sctp_m_freem(m_asconf_chk);
                return (NULL);
        }
        MCLGET(m_asconf, M_DONTWAIT);
        if ((m_asconf->m_flags & M_EXT) != M_EXT) {
                /* failed to get cluster buffer */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1)
                        printf("compose_asconf: couldn't get cluster!\n");
#endif /* SCTP_DEBUG */
                sctp_m_freem(m_asconf_chk);
                sctp_m_freem(m_asconf);
                return (NULL);
        }

        m_asconf_chk->m_len = sizeof(struct sctp_asconf_chunk);
        m_asconf->m_len = 0;
        acp = mtod(m_asconf_chk, struct sctp_asconf_chunk *);
        memset(acp, 0, sizeof(struct sctp_asconf_chunk));
        /* save pointers to lookup address and asconf params */
        lookup_ptr = (vaddr_t)(acp + 1);        /* after the header */
        ptr = mtod(m_asconf, vaddr_t);          /* beginning of cluster */

        /* fill in chunk header info */
        acp->ch.chunk_type = SCTP_ASCONF;
        acp->ch.chunk_flags = 0;
        acp->serial_number = htonl(stcb->asoc.asconf_seq_out);

        /* add parameters... up to smallest MTU allowed */
        TAILQ_FOREACH(aa, &stcb->asoc.asconf_queue, next) {
                /* get the parameter length */
                p_length = SCTP_SIZE32(aa->ap.aph.ph.param_length);
                /* will it fit in current chunk? */
                if (m_asconf->m_len + p_length > stcb->asoc.smallest_mtu) {
                        /* won't fit, so we're done with this chunk */
                        break;
                }
                /* assign (and store) a correlation id */
                aa->ap.aph.correlation_id = correlation_id++;

                /*
                 * fill in address if we're doing a delete
                 * this is a simple way for us to fill in the correlation
                 * address, which should only be used by the peer if we're
                 * deleting our source address and adding a new address
                 * (e.g. renumbering case)
                 */
                if (lookup_used == 0 &&
                    aa->ap.aph.ph.param_type == SCTP_DEL_IP_ADDRESS) {
                        struct sctp_ipv6addr_param *lookup;
                        uint16_t p_size, addr_size;

                        lookup = (struct sctp_ipv6addr_param *)lookup_ptr;
                        lookup->ph.param_type =
                            htons(aa->ap.addrp.ph.param_type);
                        if (aa->ap.addrp.ph.param_type == SCTP_IPV6_ADDRESS) {
                                /* copy IPv6 address */
                                p_size = sizeof(struct sctp_ipv6addr_param);
                                addr_size = sizeof(struct in6_addr);
                        } else {
                                /* copy IPv4 address */
                                p_size = sizeof(struct sctp_ipv4addr_param);
                                addr_size = sizeof(struct in_addr);
                        }
                        lookup->ph.param_length = htons(SCTP_SIZE32(p_size));
                        memcpy(lookup->addr, &aa->ap.addrp.addr, addr_size);
                        m_asconf_chk->m_len += SCTP_SIZE32(p_size);
                        lookup_used = 1;
                }

                /* copy into current space */
                memcpy((void *)ptr, &aa->ap, p_length);

                /* network elements and update lengths */
                aph = (struct sctp_asconf_paramhdr *) ptr;
                aap = (struct sctp_asconf_addr_param *) ptr;
                /* correlation_id is transparent to peer, no htonl needed */
                aph->ph.param_type = htons(aph->ph.param_type);
                aph->ph.param_length = htons(aph->ph.param_length);
                aap->addrp.ph.param_type = htons(aap->addrp.ph.param_type);
                aap->addrp.ph.param_length = htons(aap->addrp.ph.param_length);

                m_asconf->m_len += SCTP_SIZE32(p_length);
                ptr += SCTP_SIZE32(p_length);

                /*
                 * these params are removed off the pending list upon
                 * getting an ASCONF-ACK back from the peer, just set flag
                 */
                aa->sent = 1;
        }
        /* check to see if the lookup addr has been populated yet */
        if (lookup_used == 0) {
                /* NOTE: if the address param is optional, can skip this... */
                /* add any valid (existing) address... */
                struct sctp_ipv6addr_param *lookup;
                uint16_t p_size, addr_size;
                struct sockaddr *found_addr;
                vaddr_t addr_ptr;

                if (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_BOUNDALL)
                        found_addr = sctp_find_valid_localaddr(stcb);
                else
                        found_addr = sctp_find_valid_localaddr_ep(stcb);

                lookup = (struct sctp_ipv6addr_param *)lookup_ptr;
                if (found_addr != NULL) {
                        if (found_addr->sa_family == AF_INET6) {
                                /* copy IPv6 address */
                                lookup->ph.param_type =
                                    htons(SCTP_IPV6_ADDRESS);
                                p_size = sizeof(struct sctp_ipv6addr_param);
                                addr_size = sizeof(struct in6_addr);
                                addr_ptr = (vaddr_t)&((struct sockaddr_in6 *)
                                    found_addr)->sin6_addr;
                        } else {
                                /* copy IPv4 address */
                                lookup->ph.param_type =
                                    htons(SCTP_IPV4_ADDRESS);
                                p_size = sizeof(struct sctp_ipv4addr_param);
                                addr_size = sizeof(struct in_addr);
                                addr_ptr = (vaddr_t)&((struct sockaddr_in *)
                                    found_addr)->sin_addr;
                        }
                        lookup->ph.param_length = htons(SCTP_SIZE32(p_size));
                        memcpy(lookup->addr, (void *)addr_ptr, addr_size);
                        m_asconf_chk->m_len += SCTP_SIZE32(p_size);
                        lookup_used = 1;
                } else {
                        /* uh oh... don't have any address?? */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1)
                                printf("compose_asconf: no lookup addr!\n");
#endif /* SCTP_DEBUG */
                        /* for now, we send a IPv4 address of 0.0.0.0 */
                        lookup->ph.param_type = htons(SCTP_IPV4_ADDRESS);
                        lookup->ph.param_length = htons(SCTP_SIZE32(sizeof(struct sctp_ipv4addr_param)));
                        memset(lookup->addr, 0, sizeof(struct in_addr));
                        m_asconf_chk->m_len += SCTP_SIZE32(sizeof(struct sctp_ipv4addr_param));
                        lookup_used = 1;
                }
        }

        /* chain it all together */
        m_asconf_chk->m_next = m_asconf;
        m_asconf_chk->m_pkthdr.len = m_asconf_chk->m_len + m_asconf->m_len;
        acp->ch.chunk_length = ntohs(m_asconf_chk->m_pkthdr.len);

        /* update "sent" flag */
        stcb->asoc.asconf_sent++;

        return (m_asconf_chk);
}

/*
 * section to handle address changes before an association is up
 * eg. changes during INIT/INIT-ACK/COOKIE-ECHO handshake
 */

/*
 * processes the (local) addresses in the INIT-ACK chunk
 */
static void
sctp_process_initack_addresses(struct sctp_tcb *stcb, struct mbuf *m,
    unsigned int offset, unsigned int length)
{
        struct sctp_paramhdr tmp_param, *ph;
        uint16_t plen, ptype;
        struct sctp_ipv6addr_param addr_store;
        struct sockaddr_in6 sin6;
        struct sockaddr_in sin;
        struct sockaddr *sa;
        struct ifaddr *ifa;

#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                printf("processing init-ack addresses\n");
        }
#endif /* SCTP_DEBUG */

        /* convert to upper bound */
        length += offset;

        if ((offset + sizeof(struct sctp_paramhdr)) > length) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("process_initack_addrs: invalid offset?\n");
                }
#endif /* SCTP_DEBUG */
                return;
        }

        /* init the addresses */
        memset(&sin6, 0, sizeof(sin6));
        sin6.sin6_family = AF_INET6;
        sin6.sin6_len = sizeof(sin6);
        sin6.sin6_port = stcb->rport;

        memset(&sin, 0, sizeof(sin));
        sin.sin_len = sizeof(sin);
        sin.sin_family = AF_INET;
        sin.sin_port = stcb->rport;

        /* go through the addresses in the init-ack */
        ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
            sizeof(struct sctp_paramhdr), (uint8_t *)&tmp_param);
        while (ph != NULL) {
                ptype = ntohs(ph->param_type);
                plen = ntohs(ph->param_length);
                if (ptype == SCTP_IPV6_ADDRESS) {
                        struct sctp_ipv6addr_param *a6p;
                        /* get the entire IPv6 address param */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                printf("process_initack_addrs: checking IPv6 param\n");
                        }
#endif /* SCTP_DEBUG */
                        a6p = (struct sctp_ipv6addr_param *)
                                sctp_m_getptr(m, offset,
                                    sizeof(struct sctp_ipv6addr_param),
                                    (uint8_t *)&addr_store);
                        if (plen != sizeof(struct sctp_ipv6addr_param) ||
                            a6p == NULL) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                        printf("process_initack_addrs: invalid IPv6 param length\n");
                                }
#endif /* SCTP_DEBUG */
                                return;
                        }
                        memcpy(&sin6.sin6_addr, a6p->addr,
                            sizeof(struct in6_addr));
                        sa = (struct sockaddr *)&sin6;
                } else if (ptype == SCTP_IPV4_ADDRESS) {
                        struct sctp_ipv4addr_param *a4p;
                        /* get the entire IPv4 address param */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                printf("process_initack_addrs: checking IPv4 param\n");
                        }
#endif /* SCTP_DEBUG */
                        a4p = (struct sctp_ipv4addr_param *)sctp_m_getptr(m, offset, sizeof(struct sctp_ipv4addr_param), (uint8_t *)&addr_store);
                        if (plen != sizeof(struct sctp_ipv4addr_param) ||
                            a4p == NULL) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                        printf("process_initack_addrs: invalid IPv4 param length\n");
                                }
#endif /* SCTP_DEBUG */
                                return;
                        }
                        sin.sin_addr.s_addr = a4p->addr;
                        sa = (struct sockaddr *)&sin;
                } else {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                printf("process_initack_addrs: skipping param type=%xh\n", ptype);
                        }
#endif /* SCTP_DEBUG */
                        goto next_addr;
                }

                /* see if this address really (still) exists */
                ifa = sctp_find_ifa_by_addr(sa);
                if (ifa == NULL) {
                        /* address doesn't exist anymore */
                        int status;
                        /* are ASCONFs allowed ? */
                        if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_DO_ASCONF) &&
                            stcb->asoc.peer_supports_asconf) {
                                /* queue an ASCONF DEL_IP_ADDRESS */
                                status = sctp_asconf_queue_add_sa(stcb, sa,
                                    SCTP_DEL_IP_ADDRESS);
                                /*
                                 * if queued ok, and in correct state,
                                 * set the ASCONF timer
                                 */
                                if (status == 0 &&
                                    SCTP_GET_STATE(&stcb->asoc) ==
                                    SCTP_STATE_OPEN) {
                                        sctp_timer_start(SCTP_TIMER_TYPE_ASCONF,
                                            stcb->sctp_ep, stcb,
                                            stcb->asoc.primary_destination);
                                }
                        }
                } else {
                        /* address still exists */
                        /*
                         * if subset bound, ep addr's managed by default
                         * if not doing ASCONF, add the address to the assoc
                         */
                        if ((stcb->sctp_ep->sctp_flags &
                             SCTP_PCB_FLAGS_BOUNDALL) == 0 &&
                            (stcb->sctp_ep->sctp_flags &
                             SCTP_PCB_FLAGS_DO_ASCONF) == 0) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                        printf("process_initack_addrs: adding local addr to asoc\n");
                                }
#endif /* SCTP_DEBUG */
                                sctp_add_local_addr_assoc(stcb, ifa);
                        }
                }

        next_addr:
                /* get next parameter */
                offset += SCTP_SIZE32(plen);
                if ((offset + sizeof(struct sctp_paramhdr)) > length)
                        return;
                ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
                    sizeof(struct sctp_paramhdr), (uint8_t *)&tmp_param);
        } /* while */
}

/* FIX ME: need to verify return result for v6 address type if v6 disabled */
/*
 * checks to see if a specific address is in the initack address list
 * returns 1 if found, 0 if not
 */
static uint32_t
sctp_addr_in_initack(struct sctp_tcb *stcb, struct mbuf *m, unsigned int offset,
    unsigned int length, struct sockaddr *sa)
{
        struct sctp_paramhdr tmp_param, *ph;
        uint16_t plen, ptype;
        struct sctp_ipv6addr_param addr_store;
        struct sockaddr_in *sin;
        struct sctp_ipv4addr_param *a4p;
#ifdef INET6
        struct sockaddr_in6 *sin6, sin6_tmp;
        struct sctp_ipv6addr_param *a6p;
#endif /* INET6 */

        if (
#ifdef INET6
                (sa->sa_family != AF_INET6) &&
#endif /* INET6 */
                (sa->sa_family != AF_INET))
                return (0);

#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                printf("find_initack_addr: starting search for ");
                sctp_print_address(sa);
        }
#endif /* SCTP_DEBUG */
        /* convert to upper bound */
        length += offset;

        if ((offset + sizeof(struct sctp_paramhdr)) > length) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("find_initack_addr: invalid offset?\n");
                }
#endif /* SCTP_DEBUG */
                return (0);
        }

        /* go through the addresses in the init-ack */
        ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
            sizeof(struct sctp_paramhdr), (uint8_t *)&tmp_param);
        while (ph != NULL) {
                ptype = ntohs(ph->param_type);
                plen = ntohs(ph->param_length);
#ifdef INET6
                if (ptype == SCTP_IPV6_ADDRESS && sa->sa_family == AF_INET6) {
                        /* get the entire IPv6 address param */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                printf("addr_in_initack: checking IPv6 param\n");
                        }
#endif /* SCTP_DEBUG */
                        a6p = (struct sctp_ipv6addr_param *)
                                sctp_m_getptr(m, offset,
                                    sizeof(struct sctp_ipv6addr_param),
                                    (uint8_t *)&addr_store);
                        if (plen != sizeof(struct sctp_ipv6addr_param) ||
                            ph == NULL) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                        printf("addr_in_initack: invalid IPv6 param length\n");
                                }
#endif /* SCTP_DEBUG */
                                return (0);
                        }
                        sin6 = (struct sockaddr_in6 *)sa;
                        if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr)) {
                                /* create a copy and clear scope */
                                memcpy(&sin6_tmp, sin6,
                                    sizeof(struct sockaddr_in6));
                                sin6 = &sin6_tmp;
                                in6_clearscope(&sin6->sin6_addr);
                        }
                        if (memcmp(&sin6->sin6_addr, a6p->addr,
                            sizeof(struct in6_addr)) == 0) {
                                /* found it */
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                        printf("addr_in_initack: found IPv6 addr\n");
                                }
#endif /* SCTP_DEBUG */
                                return (1);
                        }
                } else
#endif /* INET6 */

                if (ptype == SCTP_IPV4_ADDRESS &&
                    sa->sa_family == AF_INET) {
                        /* get the entire IPv4 address param */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                printf("addr_in_initack: checking IPv4 param\n");
                        }
#endif /* SCTP_DEBUG */
                        a4p = (struct sctp_ipv4addr_param *)sctp_m_getptr(m,
                            offset, sizeof(struct sctp_ipv4addr_param),
                            (uint8_t *)&addr_store);
                        if (plen != sizeof(struct sctp_ipv4addr_param) ||
                            ph == NULL) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                        printf("addr_in_initack: invalid IPv4 param length\n");
                                }
#endif /* SCTP_DEBUG */
                                return (0);
                        }
                        sin = (struct sockaddr_in *)sa;
                        if (sin->sin_addr.s_addr == a4p->addr) {
                                /* found it */
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                        printf("addr_in_initack: found IPv4 addr\n");
                                }
#endif /* SCTP_DEBUG */
                                return (1);
                        }
                } else {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                printf("addr_in_initack: skipping param type=%xh\n", ptype);
                        }
#endif /* SCTP_DEBUG */
                }
                /* get next parameter */
                offset += SCTP_SIZE32(plen);
                if (offset + sizeof(struct sctp_paramhdr) > length)
                        return (0);
                ph = (struct sctp_paramhdr *)
                        sctp_m_getptr(m, offset, sizeof(struct sctp_paramhdr),
                            (uint8_t *)&tmp_param);
        } /* while */
        /* not found! */
#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                printf("addr_in_initack: not found!\n");
        }
#endif /* SCTP_DEBUG */
        return (0);
}

/*
 * makes sure that the current endpoint local addr list is consistent
 * with the new association (eg. subset bound, asconf allowed)
 * adds addresses as necessary
 */
static void
sctp_check_address_list_ep(struct sctp_tcb *stcb, struct mbuf *m, int offset,
    int length, struct sockaddr *init_addr)
{
        struct sctp_laddr *laddr;

        /* go through the endpoint list */
        LIST_FOREACH(laddr, &stcb->sctp_ep->sctp_addr_list, sctp_nxt_addr) {
                /* be paranoid and validate the laddr */
                if (laddr->ifa == NULL) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("check_addr_list_ep: laddr->ifa is NULL");
                        }
#endif
                        continue;
                }
                if (laddr->ifa->ifa_addr == NULL) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                                printf("check_addr_list_ep: laddr->ifa->ifa_addr is NULL");
                        }
#endif
                        continue;
                }
                /* do i have it implicitly? */
                if (sctp_cmpaddr(laddr->ifa->ifa_addr, init_addr)) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                printf("check_address_list_all: skipping ");
                                sctp_print_address(laddr->ifa->ifa_addr);
                        }
#endif /* SCTP_DEBUG */
                        continue;
                }
                /* check to see if in the init-ack */
                if (!sctp_addr_in_initack(stcb, m, offset, length,
                                          laddr->ifa->ifa_addr)) {
                        /* try to add it */
                        sctp_addr_mgmt_assoc(stcb->sctp_ep, stcb, laddr->ifa,
                            SCTP_ADD_IP_ADDRESS);
                }
        }
}

/*
 * makes sure that the current kernel address list is consistent
 * with the new association (with all addrs bound)
 * adds addresses as necessary
 */
static void
sctp_check_address_list_all(struct sctp_tcb *stcb, struct mbuf *m, int offset,
    int length, struct sockaddr *init_addr, uint16_t local_scope,
    uint16_t site_scope, uint16_t ipv4_scope, uint16_t loopback_scope)
{
        struct ifnet *ifn;
        struct ifaddr *ifa;
        int s;

        /* go through all our known interfaces */
        s = pserialize_read_enter();
        IFNET_READER_FOREACH(ifn) {
                if (loopback_scope == 0 && ifn->if_type == IFT_LOOP) {
                        /* skip loopback interface */
                        continue;
                }

                /* go through each interface address */
                IFADDR_READER_FOREACH(ifa, ifn) {
                        /* do i have it implicitly? */
                        if (sctp_cmpaddr(ifa->ifa_addr, init_addr)) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_ASCONF2) {
                                        printf("check_address_list_all: skipping ");
                                        sctp_print_address(ifa->ifa_addr);
                                }
#endif /* SCTP_DEBUG */
                                continue;
                        }
                        /* check to see if in the init-ack */
                        if (!sctp_addr_in_initack(stcb, m, offset, length,
                            ifa->ifa_addr)) {
                                /* try to add it */
                                sctp_addr_mgmt_assoc(stcb->sctp_ep, stcb,
                                    ifa, SCTP_ADD_IP_ADDRESS);
                        }
                } /* end foreach ifa */
        } /* end foreach ifn */
        pserialize_read_exit(s);
}

/*
 * validates an init-ack chunk (from a cookie-echo) with current addresses
 * adds addresses from the init-ack into our local address list, if needed
 * queues asconf adds/deletes addresses as needed and makes appropriate
 * list changes for source address selection
 * m, offset: points to the start of the address list in an init-ack chunk
 * length: total length of the address params only
 * init_addr: address where my INIT-ACK was sent from
 */
void
sctp_check_address_list(struct sctp_tcb *stcb, struct mbuf *m, int offset,
    int length, struct sockaddr *init_addr, uint16_t local_scope,
    uint16_t site_scope, uint16_t ipv4_scope, uint16_t loopback_scope)
{

        /* process the local addresses in the initack */
        sctp_process_initack_addresses(stcb, m, offset, length);

        if (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_BOUNDALL) {
                /* bound all case */
                sctp_check_address_list_all(stcb, m, offset, length, init_addr,
                    local_scope, site_scope, ipv4_scope, loopback_scope);
        } else {
                /* subset bound case */
                if (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_DO_ASCONF) {
                        /* asconf's allowed */
                        sctp_check_address_list_ep(stcb, m, offset, length,
                            init_addr);
                }
                /* else, no asconfs allowed, so what we sent is what we get */
        }
}

/*
 * sctp_bindx() support
 */
uint32_t
sctp_addr_mgmt_ep_sa(struct sctp_inpcb *inp, struct sockaddr *sa, uint16_t type)
{
        struct ifaddr *ifa;

        if (sa->sa_len == 0)
                return (EINVAL);

        ifa = sctp_find_ifa_by_addr(sa);
        if (ifa != NULL) {
#ifdef INET6
                if (ifa->ifa_addr->sa_family == AF_INET6) {
                        struct in6_ifaddr *ifa6;
                        ifa6 = (struct in6_ifaddr *)ifa;
                        if (IFA6_IS_DEPRECATED(ifa6) ||
                            (ifa6->ia6_flags & (IN6_IFF_DETACHED |
                             IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) {
                                /* Can't bind a non-existent addr. */
                                return (EINVAL);
                        }
                }
#endif /* INET6 */
                /* add this address */
                sctp_addr_mgmt_ep(inp, ifa, type);
        } else {
                /* invalid address! */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_ASCONF1) {
                        printf("addr_mgmt_ep_sa: got invalid address!\n");
                }
#endif /* SCTP_DEBUG */
                return (EADDRNOTAVAIL);
        }
        return (0);
}