/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <arpa/inet.h>
#include <assert.h>
#include <dhcpagent_ipc.h>
#include <dhcp_inittab.h>
#include <dhcp_symbol.h>
#include <dhcpagent_util.h>
#include <errno.h>
#include <execinfo.h>
#include <libnwam.h>
#include <stdlib.h>
#include <strings.h>
#include <ucontext.h>
#include <unistd.h>
#include <libscf.h>

#include "conditions.h"
#include "events.h"
#include "ncp.h"
#include "ncu.h"
#include "objects.h"
#include "util.h"

/*
 * ncu_ip.c - contains routines that are IP interface-specific for NCUs.
 */

#define STATELESS_RUNNING       (IFF_RUNNING | IFF_UP | IFF_ADDRCONF)
#define DHCP_RUNNING            (IFF_RUNNING | IFF_UP | IFF_DHCPRUNNING)

static void nwamd_dhcp(const char *, ipadm_addrobj_t, dhcp_ipc_type_t);
static void nwamd_down_interface(const char *, ipadm_addr_type_t, const char *);
static boolean_t stateless_running(const nwamd_ncu_t *);

/*
 * Given a sockaddr representation of an IPv4 or IPv6 address returns the
 * string representation. Note that 'sockaddr' should point at the correct
 * sockaddr structure for the address family (sockaddr_in for AF_INET or
 * sockaddr_in6 for AF_INET6) or alternatively at a sockaddr_storage
 * structure.
 */
static const char *
nwamd_sockaddr2str(const struct sockaddr *addr, char *str, size_t len)
{
        struct sockaddr_in *sin;
        struct sockaddr_in6 *sin6;
        const char *straddr;

        if (addr == NULL)
                return (NULL);

        if (addr->sa_family == AF_INET) {
                /* LINTED E_BAD_PTR_CAST_ALIGN */
                sin = (struct sockaddr_in *)addr;
                straddr = inet_ntop(AF_INET, (void *)&sin->sin_addr, str, len);
        } else if (addr->sa_family == AF_INET6) {
                /* LINTED E_BAD_PTR_CAST_ALIGN */
                sin6 = (struct sockaddr_in6 *)addr;
                straddr = inet_ntop(AF_INET6, (void *)&sin6->sin6_addr, str,
                    len);
        } else {
                errno = EINVAL;
                return (NULL);
        }
        return (straddr != NULL ? str : NULL);
}

void
nwamd_propogate_link_up_down_to_ip(const char *linkname, boolean_t up)
{
        nwamd_object_t ip_ncu = nwamd_ncu_object_find(NWAM_NCU_TYPE_INTERFACE,
            linkname);
        nwamd_ncu_t *ncu;

        if (ip_ncu == NULL) {
                nlog(LOG_DEBUG, "nwamd_propogate_link_up_down_to_ip: no IP NCU "
                    "for link %s, cannot propogate %s event", linkname,
                    up ? "up" : "down");
                return;
        }
        ncu = ip_ncu->nwamd_object_data;

        if (ncu->ncu_enabled) {
                if (ip_ncu->nwamd_object_aux_state ==
                    NWAM_AUX_STATE_UNINITIALIZED) {
                        nlog(LOG_DEBUG,
                            "nwamd_propogate_link_up_down_to_ip: will not "
                            "propogate link %s event as IP NCU %s is being "
                            "removed", up ? "up" : "down", linkname);
                } else {
                        nlog(LOG_DEBUG,
                            "nwamd_propogate_link_up_down_to_ip: propogating "
                            "link %s event to interface %s",
                            up ? "up" : "down", linkname);
                        nwamd_object_set_state(NWAM_OBJECT_TYPE_NCU,
                            ip_ncu->nwamd_object_name,
                            up ?
                            NWAM_STATE_OFFLINE_TO_ONLINE :
                            NWAM_STATE_ONLINE_TO_OFFLINE,
                            up ? NWAM_AUX_STATE_INITIALIZED :
                            NWAM_AUX_STATE_CONDITIONS_NOT_MET);
                }
        } else {
                nlog(LOG_DEBUG,
                    "nwamd_propogate_link_up_down_to_ip: not propogating "
                    "link %s event to interface %s, IP NCU is disabled",
                    up ? "up" : "down", linkname);
        }
        nwamd_object_release(ip_ncu);
}

/*
 * Returns the value associated with the given symbol for the given
 * interface.  The interface may be NULL, in which case the primary
 * interface is used.
 * This function substitutes the need to call dhcpinfo(1), thus it is
 * very similar to the implementation of dhcpinfo(1).
 * When multiple values need to be returned (e.g., nameservers), they
 * are separated by a space ' '.
 */
char *
nwamd_get_dhcpinfo_data(const char *sym_name, char *ifname)
{
        dhcp_symbol_t *entry;
        dhcp_optnum_t optnum;
        dhcp_ipc_request_t *request = NULL;
        dhcp_ipc_reply_t *reply;
        DHCP_OPT *opt;
        size_t opt_len;
        char *value; /* return value */
        int err;
        char errmsg[LINE_MAX];

        /* if interface is not given, change it to empty string */
        if (ifname == NULL)
                ifname = "";

        /* find code and category in dhcp_inittab(5) */
        entry = inittab_getbyname(ITAB_CAT_SITE | ITAB_CAT_STANDARD |
            ITAB_CAT_VENDOR | ITAB_CAT_FIELD, ITAB_CONS_INFO, sym_name);

        if (entry == NULL) {
                (void) snprintf(errmsg, LINE_MAX, "unknown identifier: %s",
                    sym_name);
                goto fail;
        }

        /* allocate request */
        optnum.code = entry->ds_code;
        optnum.category = entry->ds_category;
        optnum.size = entry->ds_max * inittab_type_to_size(entry);
        request = dhcp_ipc_alloc_request(DHCP_GET_TAG, ifname, &optnum,
            sizeof (dhcp_optnum_t), DHCP_TYPE_OPTNUM);
        if (request == NULL) {
                (void) snprintf(errmsg, LINE_MAX, "failed dhcp alloc request");
                goto fail;
        }

        /* make the request */
        err = dhcp_ipc_make_request(request, &reply, DHCP_IPC_WAIT_DEFAULT);
        if (err != 0 || reply->return_code != 0) {
                (void) snprintf(errmsg, LINE_MAX, "%s",
                    dhcp_ipc_strerror(err == 0 ? reply->return_code : err));
        }

        /* get data from the reply */
        opt = dhcp_ipc_get_data(reply, &opt_len, NULL);
        if (opt_len == 0) {
                (void) snprintf(errmsg, LINE_MAX, "invalid data");
                goto fail;
        }

        /* check protocol error */
        if (opt_len < 2 || (opt_len -2 != opt->len)) {
                (void) snprintf(errmsg, LINE_MAX, "data length mismatch");
                goto fail;
        }
        opt_len -= 2;

        /* decode the data into ascii */
        value = inittab_decode(entry, opt->value, opt_len, B_TRUE);
        if (value == NULL) {
                (void) snprintf(errmsg, LINE_MAX, "cannot decode reply");
                goto fail;
        }

        free(request);
        free(reply);
        return (value);

fail:
        nlog(LOG_DEBUG, "get_dhcpinfo_data() failed: %s", errmsg);
        free(request);
        free(reply);
        return (NULL);
}

void
nwamd_add_default_routes(nwamd_ncu_t *ncu)
{
        nwamd_if_t *nif = &ncu->ncu_if;
        char str[INET6_ADDRSTRLEN];

        if (nif->nwamd_if_ipv4 && nif->nwamd_if_ipv4_default_route_set) {
                struct sockaddr_in v4dest, v4mask;

                v4dest.sin_addr.s_addr = htonl(INADDR_ANY);
                v4dest.sin_family = AF_INET;

                v4mask.sin_addr.s_addr = 0;
                v4mask.sin_family = AF_INET;

                nlog(LOG_DEBUG, "nwamd_add_default_routes: adding default "
                    "route %s", nwamd_sockaddr2str((struct sockaddr *)
                    &nif->nwamd_if_ipv4_default_route, str,
                    sizeof (str)));
                nwamd_add_route((struct sockaddr *)&v4dest,
                    (struct sockaddr *)&v4mask,
                    (struct sockaddr *)&nif->nwamd_if_ipv4_default_route,
                    ncu->ncu_name);
        }

        if (nif->nwamd_if_ipv6 && nif->nwamd_if_ipv6_default_route_set) {
                struct sockaddr_in6 v6dest, v6mask;

                (void) bzero(&v6dest, sizeof (struct sockaddr_in6));
                v6dest.sin6_family = AF_INET6;

                (void) bzero(&v6mask, sizeof (struct sockaddr_in6));
                v6mask.sin6_family = AF_INET6;

                nlog(LOG_DEBUG, "nwamd_add_default_routes: adding default "
                    "route %s", nwamd_sockaddr2str((struct sockaddr *)
                    &nif->nwamd_if_ipv6_default_route, str,
                    sizeof (str)));
                nwamd_add_route((struct sockaddr *)&v6dest,
                    (struct sockaddr *)&v6mask,
                    (struct sockaddr *)&nif->nwamd_if_ipv6_default_route,
                    ncu->ncu_name);
        }
}

/*
 * Returns the nwamd_if_address structure for the given static address,
 * NULL if not found.
 */
static struct nwamd_if_address *
find_static_address(const struct sockaddr_storage *addr, const nwamd_ncu_t *ncu)
{
        struct nwamd_if_address *nifap, *nifa = ncu->ncu_if.nwamd_if_list;
        struct sockaddr_storage saddr;
        char str[INET6_ADDRSTRLEN];

        nlog(LOG_DEBUG, "find_static_address: %s",
            nwamd_sockaddr2str((struct sockaddr *)addr, str, sizeof (str)));
        for (nifap = nifa; nifap != NULL; nifap = nifap->next) {
                if (nifap->ipaddr_atype != IPADM_ADDR_STATIC ||
                    ipadm_get_addr(nifap->ipaddr, &saddr) != IPADM_SUCCESS)
                        continue;

                if (sockaddrcmp(addr, &saddr))
                        return (nifap);
        }
        return (NULL);
}

/*
 * Returns the nwamd_if_address structure representing the non-static address
 * in the NCU.  For IPv6, both stateless and stateful (DHCPv6) share the same
 * nwamd_if_address.  Will only return the nwamd_if_address if the relevant
 * address is configured (v4 DHCP, v6 either stateless or stateless) for the
 * NCU.  Returns NULL if the structure is not found.
 */
static struct nwamd_if_address *
find_nonstatic_address(const nwamd_ncu_t *ncu, sa_family_t family)
{
        struct nwamd_if_address *nifap, *nifa = ncu->ncu_if.nwamd_if_list;
        const nwamd_if_t *u_if = &ncu->ncu_if;

        nlog(LOG_DEBUG, "find_nonstatic_address for %s %s",
            (family == AF_INET ? "IPv4" : "IPv6"),  ncu->ncu_name);
        for (nifap = nifa; nifap != NULL; nifap = nifap->next) {
                if (nifap->ipaddr_atype == IPADM_ADDR_STATIC)
                        continue;

                if (family == AF_INET) {
                        if (nifap->ipaddr_atype == IPADM_ADDR_DHCP &&
                            u_if->nwamd_if_dhcp_requested)
                                return (nifap);
                } else if (family == AF_INET6) {
                        if (nifap->ipaddr_atype == IPADM_ADDR_IPV6_ADDRCONF &&
                            (u_if->nwamd_if_stateful_requested ||
                            u_if->nwamd_if_stateless_requested))
                                return (nifap);
                }
        }
        return (NULL);
}

/*
 * Returns the nwamd_if_address structure that configured the given address,
 * NULL if not found.
 */
static struct nwamd_if_address *
find_configured_address(const struct sockaddr_storage *addr,
    const nwamd_ncu_t *ncu)
{
        struct nwamd_if_address *nifap, *nifa = ncu->ncu_if.nwamd_if_list;
        char str[INET6_ADDRSTRLEN];

        nlog(LOG_DEBUG, "find_configured_address: %s",
            nwamd_sockaddr2str((struct sockaddr *)addr, str, sizeof (str)));
        for (nifap = nifa; nifap != NULL; nifap = nifap->next) {
                if (sockaddrcmp(addr, &nifap->conf_addr) ||
                    sockaddrcmp(addr, &nifap->conf_stateless_addr))
                        return (nifap);
        }
        return (NULL);
}

/*
 * Are one or more static addresses configured?
 */
boolean_t
nwamd_static_addresses_configured(nwamd_ncu_t *ncu, sa_family_t family)
{
        struct nwamd_if_address *n;

        for (n = ncu->ncu_if.nwamd_if_list; n != NULL; n = n->next) {
                if (n->ipaddr_atype != IPADM_ADDR_STATIC)
                        continue;
                if ((family == AF_UNSPEC || family == n->family) &&
                    n->configured)
                        return (B_TRUE);
        }
        nlog(LOG_DEBUG, "no static addresses configured for %s", ncu->ncu_name);
        return (B_FALSE);
}

/*
 * Is DHCP probably managing an address on this index.  We decide that it is
 * probably managing an address if there is an interface with IFF_DHCP set
 * that isn't in our set of static addresses.  Note that IFF_DHCP gets set
 * on static addresses when we do a dhcp inform and if that list has changed
 * recently then the result of this function could be erronous.
 */
boolean_t
nwamd_dhcp_managing(int protocol, nwamd_ncu_t *ncu)
{
        struct sockaddr_storage addr;
        uint64_t flags;
        boolean_t rv = B_FALSE;
        ipadm_addr_info_t *addrinfo, *a;
        ipadm_status_t ipstatus;

        if ((ipstatus = ipadm_addr_info(ipadm_handle, ncu->ncu_name, &addrinfo,
            0, 0)) != IPADM_SUCCESS) {
                nlog(LOG_ERR, "nwamd_dhcp_managing: "
                    "ipadm_addr_info failed for %s: %s",
                    ncu->ncu_name, ipadm_status2str(ipstatus));
                return (B_FALSE);
        }

        for (a = addrinfo; a != NULL; a = IA_NEXT(a)) {
                /*
                 * WARNING: This memcpy() assumes knowledge of the
                 * implementation of getifaddrs() and that it always
                 * uses sockaddr_storage as the backing store for
                 * address information, thus making it possible to
                 * copy the entire structure rather than do it on
                 * the size of the sockaddr according to family.
                 * This assumption is made elsewhere in this file.
                 */
                (void) memcpy(&addr, a->ia_ifa.ifa_addr, sizeof (addr));

                /* is this address an expected static one? */
                if (find_static_address(&addr, ncu) != NULL)
                        continue;

                /*
                 * For IPv4, DHCPRUNNING flag is set when dhcpagent is in
                 * the process of getting an address, but doesn't have one
                 * yet (interface has 0.0.0.0).  For IPv6, DHCPRUNNING flag
                 * is set on the link-local address if trying to get a
                 * stateful address.  In both cases, consider the interface
                 * as not being managed by DHCP and skip checking of flags.
                 */
                if ((protocol == AF_INET &&
                    ((struct sockaddr_in *)&addr)->sin_addr.s_addr ==
                    INADDR_ANY) ||
                    (protocol == AF_INET6 &&
                    IN6_IS_ADDR_LINKLOCAL(
                    &((struct sockaddr_in6 *)&addr)->sin6_addr))) {
                        continue;
                }

                flags = a->ia_ifa.ifa_flags;
                if (flags & IFF_DHCPRUNNING) {
                        /*
                         * If we get here we have an address that has the
                         * DHCP flag set and isn't an expected static address.
                         */
                        rv = B_TRUE;
                        break;
                }
        }

        ipadm_free_addr_info(addrinfo);
        return (rv);
}

/*
 * Return B_TRUE if IPv4 is requested in the given NCU.
 */
static boolean_t
nwamd_v4_requested(nwamd_ncu_t *ncu)
{
        boolean_t anyv4_requested;
        nwamd_if_t *u_if;

        anyv4_requested = B_FALSE;
        u_if = &ncu->ncu_if;
        if (u_if->nwamd_if_dhcp_requested) {
                anyv4_requested = B_TRUE;
        } else {
                struct nwamd_if_address *n;

                for (n = u_if->nwamd_if_list; n != NULL; n = n->next) {
                        if (n->family == AF_INET &&
                            n->ipaddr_atype == IPADM_ADDR_STATIC)
                                break;
                }
                if (n != NULL)
                        anyv4_requested = B_TRUE;
        }

        return (anyv4_requested);
}

/*
 * Returns B_TRUE if IPv6 is requested in the given NCU.
 */
static boolean_t
nwamd_v6_requested(nwamd_ncu_t *ncu)
{
        boolean_t anyv6_requested;
        nwamd_if_t *u_if;

        anyv6_requested = B_FALSE;
        u_if = &ncu->ncu_if;
        if (u_if->nwamd_if_stateful_requested ||
            u_if->nwamd_if_stateless_requested) {
                anyv6_requested = B_TRUE;
        } else {
                struct nwamd_if_address *n;

                for (n = u_if->nwamd_if_list; n != NULL; n = n->next) {
                        if (n->family == AF_INET6 &&
                            n->ipaddr_atype == IPADM_ADDR_STATIC)
                                break;
                }
                if (n != NULL)
                        anyv6_requested = B_TRUE;
        }

        return (anyv6_requested);
}

/*
 * Bring up the ncu if we have the right combination of requested configuration
 * and actual configuration and up is true, or bring down the ncu if no
 * addresses are configured, and up is false.
 */
static void
interface_ncu_up_down(nwamd_ncu_t *ncu, boolean_t up)
{
        boolean_t ncu_online;
        char *name;

        assert(ncu->ncu_type == NWAM_NCU_TYPE_INTERFACE);

        /*
         * If V4 with or without V6 is configured then one of its interfaces
         * needs to be up for the ncu to come online.  If only V6 is requested
         * then one of its interfaces needs to be up for the ncu to come online.
         */
        ncu_online = B_FALSE;
        if (nwamd_v4_requested(ncu)) {
                if (nwamd_dhcp_managing(AF_INET, ncu) ||
                    nwamd_static_addresses_configured(ncu, AF_INET))
                        ncu_online = B_TRUE;
        } else if (nwamd_v6_requested(ncu)) {
                if ((nwamd_dhcp_managing(AF_INET6, ncu) ||
                    stateless_running(ncu) ||
                    nwamd_static_addresses_configured(ncu, AF_INET6)))
                        ncu_online = B_TRUE;
        }

        if (nwam_ncu_name_to_typed_name(ncu->ncu_name, ncu->ncu_type, &name) !=
            NWAM_SUCCESS) {
                nlog(LOG_DEBUG, "interface_ncu_up_down: "
                    "nwam_ncu_name_to_typed_name failed");
                return;
        }
        if (ncu_online && up) {
                nlog(LOG_DEBUG, "interface_ncu_up_down: "
                    "bringing %s up", name);
                nwamd_object_set_state(NWAM_OBJECT_TYPE_NCU, name,
                    NWAM_STATE_OFFLINE_TO_ONLINE, NWAM_AUX_STATE_UP);
        } else if (!ncu_online && !up) {
                nlog(LOG_DEBUG, "interface_ncu_up_down: "
                    "bringing %s down", name);
                nwamd_object_set_state(NWAM_OBJECT_TYPE_NCU, name,
                    NWAM_STATE_ONLINE_TO_OFFLINE,
                    NWAM_AUX_STATE_DOWN);
        }

        free(name);
}

static void
interface_ncu_up(nwamd_ncu_t *ncu)
{
        interface_ncu_up_down(ncu, B_TRUE);
}

static void
interface_ncu_down(nwamd_ncu_t *ncu)
{
        interface_ncu_up_down(ncu, B_FALSE);
}

static boolean_t
stateless_running(const nwamd_ncu_t *ncu)
{
        ipadm_addr_info_t *ainfo, *ainfop;
        ipadm_status_t ipstatus;
        boolean_t rv = B_FALSE;
        uint64_t flags;

        if ((ipstatus = ipadm_addr_info(ipadm_handle, ncu->ncu_name, &ainfo,
            0, 0)) != IPADM_SUCCESS) {
                nlog(LOG_ERR, "stateless_running: "
                    "ipadm_addr_info failed for %s: %s",
                    ncu->ncu_name, ipadm_status2str(ipstatus));
                return (B_FALSE);
        }

        for (ainfop = ainfo; ainfop != NULL; ainfop = IA_NEXT(ainfop)) {
                if (ainfop->ia_ifa.ifa_addr->sa_family != AF_INET6)
                        continue;
                flags = ainfop->ia_ifa.ifa_flags;
                if (flags & STATELESS_RUNNING) {
                        rv = B_TRUE;
                        break;
                }
        }
        ipadm_free_addr_info(ainfo);
        return (rv);
}

/*
 * Returns the addrinfo associated with the given address.  There is always
 * only one addrinfo for each address.
 */
static boolean_t
addrinfo_for_addr(const struct sockaddr_storage *caddr, const char *ifname,
    ipadm_addr_info_t **ainfo)
{
        ipadm_addr_info_t *addrinfo, *ainfop, *last = NULL;
        ipadm_status_t ipstatus;

        ipstatus = ipadm_addr_info(ipadm_handle, ifname, &addrinfo, 0, 0);
        if (ipstatus != IPADM_SUCCESS) {
                nlog(LOG_INFO, "addrinfo_for_addr: "
                    "ipadm_addr_info failed for %s: %s",
                    ifname, ipadm_status2str(ipstatus));
                return (B_FALSE);
        }

        *ainfo = NULL;
        for (ainfop = addrinfo; ainfop != NULL; ainfop = IA_NEXT(ainfop)) {
                struct sockaddr_storage addr;

                (void) memcpy(&addr, ainfop->ia_ifa.ifa_addr, sizeof (addr));
                /*
                 * If addresses match, rearrange pointers so that addrinfo
                 * does not contain a, and return a.
                 */
                if (sockaddrcmp(&addr, caddr)) {
                        if (last != NULL)
                                last->ia_ifa.ifa_next = ainfop->ia_ifa.ifa_next;
                        else
                                addrinfo = IA_NEXT(ainfop);

                        ainfop->ia_ifa.ifa_next = NULL;
                        *ainfo = ainfop;
                        break;
                }
                last = ainfop;
        }
        ipadm_free_addr_info(addrinfo);
        return (*ainfo == NULL ? B_FALSE : B_TRUE);
}

/*
 * Returns B_TRUE if the addrinfo associated with the given ipaddr using its
 * aobjname is found.  An addrinfo list is created and returned in ainfo.
 * Stateless and stateful IPv6 addrinfo have the same aobjname, thus the need
 * to create a list of addrinfo.
 */
static boolean_t
addrinfo_for_ipaddr(ipadm_addrobj_t ipaddr, const char *ifname,
    ipadm_addr_info_t **ainfo)
{
        char aobjname[IPADM_AOBJSIZ];
        ipadm_addr_info_t *addrinfo, *ainfop;
        ipadm_addr_info_t *last = NULL;
        ipadm_status_t ipstatus;

        ipstatus = ipadm_get_aobjname(ipaddr, aobjname, sizeof (aobjname));
        if (ipstatus != IPADM_SUCCESS)
                return (B_FALSE);

        ipstatus = ipadm_addr_info(ipadm_handle, ifname, &addrinfo, 0, 0);
        if (ipstatus != IPADM_SUCCESS) {
                nlog(LOG_INFO, "addrinfo_for_ipaddr: "
                    "ipadm_addr_info failed for %s: %s",
                    ifname, ipadm_status2str(ipstatus));
                return (B_FALSE);
        }

        *ainfo = NULL;
        ainfop = addrinfo;
        while (ainfop != NULL) {
                /* If aobjnames match, rearrange pointers to create new list */
                if (strcmp(ainfop->ia_aobjname, aobjname) == 0) {
                        ipadm_addr_info_t *match = ainfop;

                        ainfop = IA_NEXT(ainfop); /* move iterator */
                        if (last != NULL)
                                last->ia_ifa.ifa_next = match->ia_ifa.ifa_next;
                        else
                                addrinfo = ainfop;
                        if (*ainfo == NULL)
                                match->ia_ifa.ifa_next = NULL;
                        else
                                match->ia_ifa.ifa_next = &(*ainfo)->ia_ifa;
                        *ainfo = match;
                } else {
                        last = ainfop;
                        ainfop = IA_NEXT(ainfop);
                }
        }
        ipadm_free_addr_info(addrinfo);
        return (*ainfo == NULL ? B_FALSE : B_TRUE);
}

/*
 * Add the address provided in the nwamd_if_address.  If DHCP is required,
 * start DHCP.  If a static address is configured, create the address; then do
 * a DHCP_INFORM (in a separate thread) to get other networking configuration
 * parameters.  RTM_NEWADDRs - translated into IF_STATE events - will then
 * finish the job of bringing the NCU online.
 */
static boolean_t
add_ip_address(const char *ifname, const struct nwamd_if_address *nifa,
    boolean_t *do_inform)
{
        ipadm_status_t ipstatus;
        ipadm_addr_info_t *addrinfo = NULL;
        uint64_t flags;

        if (nifa->ipaddr_atype == IPADM_ADDR_DHCP) {
                /*
                 * To make getting a DHCP address asynchronous, call
                 * ipadm_create_addr() in a new thread.
                 */
                nlog(LOG_DEBUG, "add_ip_address: "
                    "adding IPv4 DHCP address on %s", ifname);
                nwamd_dhcp(ifname, nifa->ipaddr, DHCP_START);
        } else {
                nlog(LOG_DEBUG, "add_ip_address: adding %s address on %s",
                    (nifa->ipaddr_atype == IPADM_ADDR_STATIC ?
                    "STATIC" : "IPv6 ADDRCONF"), ifname);
                if ((ipstatus = ipadm_create_addr(ipadm_handle, nifa->ipaddr,
                    IPADM_OPT_ACTIVE | IPADM_OPT_UP)) != IPADM_SUCCESS) {
                        nlog(LOG_ERR, "add_ip_address: "
                            "ipadm_create_addr failed on %s: %s",
                            ifname, ipadm_status2str(ipstatus));
                        return (B_FALSE);
                }
                /*
                 * When creating a static address, ipadm_create_addr() returns
                 * SUCCESS even if duplicate address is detected.  Retrieve
                 * the addrinfo to get the flags.
                 */
                if (nifa->ipaddr_atype == IPADM_ADDR_STATIC) {
                        /*
                         * Since we are configuring a static address, there
                         * will be just *ONE* addrinfo with the aobjname in
                         * nifa->ipaddr.
                         */
                        if (!addrinfo_for_ipaddr(nifa->ipaddr, ifname,
                            &addrinfo)) {
                                nlog(LOG_ERR, "add_ip_address: "
                                    "could not find addrinfo on %s", ifname);
                                return (B_FALSE);
                        }

                        flags = addrinfo->ia_ifa.ifa_flags;
                        ipadm_free_addr_info(addrinfo);
                        if (flags & IFF_DUPLICATE) {
                                char *object_name;
                                nwam_error_t err;

                                nlog(LOG_INFO, "add_ip_address: "
                                    "duplicate address detected on %s", ifname);
                                if ((err = nwam_ncu_name_to_typed_name(ifname,
                                    NWAM_NCU_TYPE_INTERFACE, &object_name))
                                    == NWAM_SUCCESS) {
                                        nwamd_object_set_state(
                                            NWAM_OBJECT_TYPE_NCU,
                                            object_name, NWAM_STATE_MAINTENANCE,
                                            NWAM_AUX_STATE_IF_DUPLICATE_ADDR);
                                        free(object_name);
                                } else {
                                        nlog(LOG_ERR, "add_ip_address: "
                                            "could not create state event "
                                            "for %s: %s",
                                            ifname, nwam_strerror(err));
                                }
                                return (B_FALSE);
                        }
                        /*
                         * Do DHCP_INFORM using async ipadm_refresh_addr().
                         * Only need to do this once per interface, and we
                         * do *not* need to do it if we are also getting a
                         * dhcp lease; so we only send the INFORM if the
                         * passed-in flag says to, and we clear the flag
                         * once we've initiated the INFORM transaction.
                         */
                        if (*do_inform) {
                                nwamd_dhcp(ifname, nifa->ipaddr, DHCP_INFORM);
                                *do_inform = B_FALSE;
                        }
                }
        }

        return (B_TRUE);
}

/*
 * Adds addresses for the given NCU.
 */
void
nwamd_configure_interface_addresses(nwamd_ncu_t *ncu)
{
        struct nwamd_if_address *nifap, *nifa = ncu->ncu_if.nwamd_if_list;
        boolean_t do_inform;

        /* only need an inform if we're not also getting a dhcp lease */
        do_inform = !ncu->ncu_if.nwamd_if_dhcp_requested;

        nlog(LOG_DEBUG, "nwamd_configure_interface_addresses(%s)",
            ncu->ncu_name);

        for (nifap = nifa; nifap != NULL; nifap = nifap->next) {
                if (nifap->configured)
                        continue;

                nifap->configured = add_ip_address(ncu->ncu_name, nifap,
                    &do_inform);
        }
}

/*
 * This event tells us that an interface address has appeared or disappeared,
 * or that the interface flags on an interface have changed.
 */
void
nwamd_ncu_handle_if_state_event(nwamd_event_t event)
{
        nwam_event_t evm;
        nwamd_object_t ncu_obj;
        nwamd_ncu_t *ncu;
        nwam_state_t state;
        nwam_aux_state_t aux_state;

        ncu_obj = nwamd_object_find(NWAM_OBJECT_TYPE_NCU,
            event->event_object);
        if (ncu_obj == NULL) {
                nlog(LOG_INFO, "nwamd_ncu_handle_if_state_event: no object %s",
                    event->event_object);
                nwamd_event_do_not_send(event);
                return;
        }
        ncu = ncu_obj->nwamd_object_data;
        evm = event->event_msg;
        state = ncu_obj->nwamd_object_state;
        aux_state = ncu_obj->nwamd_object_aux_state;

        nlog(LOG_DEBUG, "nwamd_ncu_handle_if_state_event: "
            "if %s, state (%s, %s)", event->event_object,
            nwam_state_to_string(state), nwam_aux_state_to_string(aux_state));

        /* Ensure object is in correct state to handle IF state events */
        switch (state) {
        case NWAM_STATE_OFFLINE_TO_ONLINE:
                if (aux_state != NWAM_AUX_STATE_IF_WAITING_FOR_ADDR &&
                    aux_state != NWAM_AUX_STATE_IF_DHCP_TIMED_OUT) {
                        nlog(LOG_DEBUG, "nwamd_ncu_handle_if_state_event: "
                            "if %s is in invalid aux state %s for IF_STATE "
                            "events", event->event_object,
                            nwam_aux_state_to_string(aux_state));
                        nwamd_event_do_not_send(event);
                        nwamd_object_release(ncu_obj);
                        return;
                }
                break;
        case NWAM_STATE_ONLINE:
        /*
         * We can get addresses from DHCP after we've taken the interface down.
         * We deal with those below.
         */
        case NWAM_STATE_ONLINE_TO_OFFLINE:
        case NWAM_STATE_OFFLINE:
                break;
        default:
                nlog(LOG_DEBUG, "nwamd_ncu_handle_if_state_event: "
                    "if %s is in invalid state %s for IF_STATE events",
                    event->event_object, nwam_state_to_string(state));
                nwamd_event_do_not_send(event);
                nwamd_object_release(ncu_obj);
                return;
        }

        if (evm->nwe_data.nwe_if_state.nwe_addr_valid) {
                struct nwam_event_if_state *if_state;
                char addrstr[INET6_ADDRSTRLEN];
                boolean_t static_addr = B_FALSE, addr_added;
                boolean_t v4dhcp_running, v6dhcp_running, stateless_running;
                ipadm_addr_info_t *ai = NULL, *addrinfo = NULL;
                boolean_t stateless_ai_found = B_FALSE;
                boolean_t stateful_ai_found = B_FALSE;
                struct nwamd_if_address *nifa = NULL;
                nwamd_if_t *u_if;
                struct sockaddr_storage *addr, ai_addr, *aip = NULL;
                ushort_t family;
                uint64_t flags = 0;

                if_state = &evm->nwe_data.nwe_if_state;
                u_if = &ncu->ncu_if;
                family = if_state->nwe_addr.ss_family;
                addr = &if_state->nwe_addr;
                addr_added = if_state->nwe_addr_added;

                v4dhcp_running = B_FALSE;
                v6dhcp_running = B_FALSE;
                stateless_running = B_FALSE;

                nlog(LOG_DEBUG,
                    "nwamd_ncu_handle_if_state_event: addr %s %s",
                    nwamd_sockaddr2str((struct sockaddr *)addr, addrstr,
                    sizeof (addrstr)), addr_added ? "added" : "removed");

                /*
                 * Need to get flags for this interface.  Get the addrinfo for
                 * the address that generated this IF_STATE event.
                 */
                if (addr_added) {
                        /*
                         * Address was added.  Find the addrinfo for this
                         * address and the nwamd_if_address corresponding to
                         * this address.
                         */
                        if (!addrinfo_for_addr(addr, ncu->ncu_name, &ai)) {
                                nlog(LOG_ERR,
                                    "nwamd_ncu_handle_if_state_event: "
                                    "addrinfo doesn't exist for %s", addrstr);
                                nwamd_event_do_not_send(event);
                                goto valid_done;
                        }
                        addrinfo = ai;
                        flags = addrinfo->ia_ifa.ifa_flags;
                        (void) memcpy(&ai_addr, addrinfo->ia_ifa.ifa_addr,
                            sizeof (ai_addr));
                        aip = &ai_addr;

                        if (addrinfo->ia_atype == IPADM_ADDR_IPV6_ADDRCONF ||
                            addrinfo->ia_atype == IPADM_ADDR_DHCP)
                                nifa = find_nonstatic_address(ncu, family);
                        else if (addrinfo->ia_atype == IPADM_ADDR_STATIC)
                                nifa = find_static_address(addr, ncu);

                        /*
                         * If nwamd_if_address is not found, then this address
                         * isn't one that nwamd created.  Remove it.
                         */
                        if (nifa == NULL) {
                                nlog(LOG_ERR,
                                    "nwamd_ncu_handle_if_state_event: "
                                    "address %s not managed by nwam added, "
                                    "removing it", addrstr);
                                nwamd_down_interface(addrinfo->ia_aobjname,
                                    addrinfo->ia_atype, ncu->ncu_name);
                                nwamd_event_do_not_send(event);
                                goto valid_done;
                        }

                        /* check flags to determine how intf is configured */
                        stateless_running = (family == AF_INET6) &&
                            ((flags & STATELESS_RUNNING) == STATELESS_RUNNING);
                        v4dhcp_running = (family == AF_INET) &&
                            ((flags & DHCP_RUNNING) == DHCP_RUNNING);
                        v6dhcp_running = (family == AF_INET6) &&
                            ((flags & DHCP_RUNNING) == DHCP_RUNNING);
                        static_addr = (addrinfo->ia_atype == IPADM_ADDR_STATIC);

                        /* copy the configured address into nwamd_if_address */
                        if (stateless_running) {
                                (void) memcpy(&nifa->conf_stateless_addr,
                                    addrinfo->ia_ifa.ifa_addr,
                                    sizeof (struct sockaddr_storage));
                        } else {
                                (void) memcpy(&nifa->conf_addr,
                                    addrinfo->ia_ifa.ifa_addr,
                                    sizeof (struct sockaddr_storage));
                        }

                } else {
                        /*
                         * Address was removed.  Find the nwamd_if_address
                         * that configured this address.
                         */
                        nifa = find_configured_address(addr, ncu);
                        if (nifa == NULL) {
                                nlog(LOG_ERR,
                                    "nwamd_ncu_handle_if_state_event: "
                                    "address %s not managed by nwam removed, "
                                    "nothing to do", addrstr);
                                nwamd_event_do_not_send(event);
                                goto valid_done;
                        }

                        if (addrinfo_for_ipaddr(nifa->ipaddr, ncu->ncu_name,
                            &ai)) {
                                ipadm_addr_info_t *a;
                                for (a = ai; a != NULL; a = IA_NEXT(a)) {
                                        struct sockaddr_storage stor;

                                        (void) memcpy(&stor, a->ia_ifa.ifa_addr,
                                            sizeof (stor));
                                        /*
                                         * Since multiple addrinfo can have
                                         * the same ipaddr, find the one for
                                         * the address that generated this
                                         * state event.
                                         */
                                        if (sockaddrcmp(addr, &stor)) {
                                                flags = a->ia_ifa.ifa_flags;
                                                (void) memcpy(&ai_addr,
                                                    a->ia_ifa.ifa_addr,
                                                    sizeof (ai_addr));
                                                aip = &ai_addr;
                                                addrinfo = a;
                                        }
                                        /*
                                         * Stateful and stateless IPv6
                                         * addrinfo have the same aobjname.
                                         * Use the flags to determine which
                                         * address is present in the system.
                                         */
                                        if (family == AF_INET6) {
                                                stateless_ai_found =
                                                    (a->ia_ifa.ifa_flags &
                                                    STATELESS_RUNNING);
                                                stateful_ai_found =
                                                    (a->ia_ifa.ifa_flags &
                                                    DHCP_RUNNING);
                                        }
                                }
                        }
                }

                /* Set the flags in the event for listeners */
                evm->nwe_data.nwe_if_state.nwe_flags = flags;

                if (family == AF_INET && !addr_added) {
                        /*
                         * Check for failure due to CR 6745448: if we get a
                         * report that an address has been deleted, then check
                         * for interface up, datalink down, and actual address
                         * non-zero.  If that combination is seen, then this is
                         * a DHCP cached lease, and we need to remove it from
                         * the system, or it'll louse up the kernel routes
                         * (which aren't smart enough to avoid dead
                         * interfaces).
                         */
                        if (((struct sockaddr_in *)addr)->sin_addr.s_addr
                            == INADDR_ANY && aip != 0) {
                                struct sockaddr_in *a;
                                char astr[INET6_ADDRSTRLEN];
                                a = (struct sockaddr_in *)aip;

                                if ((flags & IFF_UP) &&
                                    !(flags & IFF_RUNNING) &&
                                    a->sin_addr.s_addr != INADDR_ANY) {
                                        nlog(LOG_DEBUG,
                                            "nwamd_ncu_handle_if_state_event: "
                                            "bug workaround: clear out addr "
                                            "%s on %s", nwamd_sockaddr2str
                                            ((struct sockaddr *)a, astr,
                                            sizeof (astr)),
                                            ncu->ncu_name);
                                        nwamd_down_interface(
                                            addrinfo->ia_aobjname,
                                            IPADM_ADDR_DHCP, ncu->ncu_name);
                                }
                                goto valid_done;
                        }
                }

                /*
                 * If we received an RTM_NEWADDR and the IFF_UP flags has not
                 * been set, ignore this IF_STATE event.  Once the IFF_UP flag
                 * is set, we'll get another RTM_NEWADDR message.
                 */
                if (addr_added & !(flags & IFF_UP)) {
                        nlog(LOG_INFO, "nwamd_ncu_handle_if_state_event: "
                            "address %s added on %s without IFF_UP flag (%x), "
                            "ignoring IF_STATE event",
                            addrstr, ncu->ncu_name, flags);
                        nwamd_event_do_not_send(event);
                        goto valid_done;
                }

                /*
                 * Has the address really been removed?  Sometimes spurious
                 * RTM_DELADDRs are generated, so we need to ensure that
                 * the address is really gone.  If IFF_DUPLICATE is set,
                 * we're getting the RTM_DELADDR due to DAD, so don't test
                 * in that case.
                 */
                if (!addr_added && !(flags & IFF_DUPLICATE)) {
                        if (aip != 0 && sockaddrcmp(addr, aip)) {
                                nlog(LOG_INFO,
                                    "nwamd_ncu_handle_if_state_event: "
                                    "address %s is not really gone from %s, "
                                    "ignoring IF_STATE event",
                                    addrstr, ncu->ncu_name);
                                nwamd_event_do_not_send(event);
                                goto valid_done;
                        }
                }

                if (addr_added) {
                        /*
                         * Address has been added.
                         *
                         * We need to make sure that we really want to keep
                         * this address.  There is a race where we requested an
                         * address but by the time we got here we don't really
                         * want it and need to remove it.
                         *
                         * Once we decide we want the address adjust the ncu
                         * state accordingly.  For example if this address is
                         * enough move online.
                         */
                        if (u_if->nwamd_if_dhcp_requested && v4dhcp_running) {
                                u_if->nwamd_if_dhcp_configured = B_TRUE;
                        } else if (u_if->nwamd_if_stateful_requested &&
                            v6dhcp_running) {
                                u_if->nwamd_if_stateful_configured = B_TRUE;
                        } else if (u_if->nwamd_if_stateless_requested &&
                            stateless_running) {
                                u_if->nwamd_if_stateless_configured = B_TRUE;
                        } else if (!static_addr) {
                                /*
                                 * This is something we didn't expect.  Remove
                                 * the address.
                                 */
                                nwamd_down_interface(addrinfo->ia_aobjname,
                                    addrinfo->ia_atype, ncu->ncu_name);
                                nifa->configured = B_FALSE;
                                goto valid_done;
                        }

                        /*
                         * The address looks valid so mark configured and
                         * move online if we either have a v4 address if
                         * v4 is configured or a v6 address if only v6 is
                         * configured.
                         */
                        nifa->configured = B_TRUE;
                        if (state != NWAM_STATE_ONLINE)
                                interface_ncu_up(ncu);

                        /*
                         * Refresh network/location since we may also have other
                         * DHCP information.  We might have to restore it first
                         * in case it is in maintenance.
                         */
                        nlog(LOG_DEBUG, "nwamd_handle_if_state_event: "
                            "refreshing %s as we may have other "
                            "DHCP information", NET_LOC_FMRI);
                        (void) smf_restore_instance(NET_LOC_FMRI);
                        if (smf_refresh_instance(NET_LOC_FMRI) != 0) {
                                nlog(LOG_ERR,
                                    "nwamd_ncu_handle_if_state_"
                                    "event: refresh of %s "
                                    "failed", NET_LOC_FMRI);
                        }

                } else if (state == NWAM_STATE_ONLINE ||
                    state == NWAM_STATE_OFFLINE_TO_ONLINE) {
                        /*
                         * Address has been removed.  Only pay attention to
                         * disappearing addresses if we are online or coming
                         * online.
                         *
                         * Undo whatever configuration is necessary.  Note
                         * that this may or may not cause the NCU to go down.
                         * We can get RTM_DELADDRs for duplicate addresses
                         * so deal with this seperately.
                         */
                        nifa->configured = B_FALSE;

                        if (!static_addr && family == AF_INET) {
                                u_if->nwamd_if_dhcp_configured = B_FALSE;
                        } else if (!static_addr && family == AF_INET6) {
                                /*
                                 * The address is already gone.  When looking
                                 * for the addrinfo (using aobjname in
                                 * ipaddr), we found addrinfo for either one
                                 * or both stateless and stateful.  Using the
                                 * flags we determined whether each was
                                 * configured or not.  Update the flags here
                                 * accordingly.
                                 */
                                u_if->nwamd_if_stateful_configured =
                                    stateless_ai_found;
                                u_if->nwamd_if_stateless_configured =
                                    stateful_ai_found;
                        }

                        if (flags & IFF_DUPLICATE) {
                                nlog(LOG_INFO,
                                    "nwamd_ncu_handle_if_state_event: "
                                    "duplicate address detected on %s",
                                    ncu->ncu_name);
                                nwamd_object_set_state(NWAM_OBJECT_TYPE_NCU,
                                    event->event_object,
                                    NWAM_STATE_MAINTENANCE,
                                    NWAM_AUX_STATE_IF_DUPLICATE_ADDR);
                        } else {
                                interface_ncu_down(ncu);
                        }
                }
valid_done:
                ipadm_free_addr_info(ai);
        }
        nwamd_object_release(ncu_obj);
}

void
nwamd_ncu_handle_if_action_event(nwamd_event_t event)
{
        nwamd_object_t ncu_obj;

        nlog(LOG_DEBUG, "if action event %s",
            event->event_object[0] == '\0' ? "n/a" : event->event_object);

        ncu_obj = nwamd_object_find(NWAM_OBJECT_TYPE_NCU, event->event_object);
        if (ncu_obj == NULL) {
                nlog(LOG_ERR, "nwamd_ncu_handle_if_action_event: no object");
                nwamd_event_do_not_send(event);
                return;
        }
        nwamd_object_release(ncu_obj);
}

/*
 * Remove the address in the given aobjname.  IPADM_OPT_RELEASE is specified
 * for a DHCP address and specifies that the DHCP lease should also be released.
 * ifname is only used for nlog().
 */
static void
nwamd_down_interface(const char *aobjname, ipadm_addr_type_t atype,
    const char *ifname)
{
        ipadm_status_t ipstatus;
        uint32_t rflags = (atype == IPADM_ADDR_DHCP ? IPADM_OPT_RELEASE : 0);

        nlog(LOG_DEBUG, "nwamd_down_interface: %s [aobjname = %s]",
            ifname, aobjname);
        if ((ipstatus = ipadm_delete_addr(ipadm_handle, aobjname,
            IPADM_OPT_ACTIVE | rflags)) != IPADM_SUCCESS) {
                nlog(LOG_ERR, "nwamd_down_interface: "
                    "ipadm_delete_addr failed on %s: %s",
                    ifname, ipadm_status2str(ipstatus));
        }
}

static void
unconfigure_addresses(nwamd_ncu_t *ncu, sa_family_t af)
{
        struct nwamd_if_address *nifap, *nifa = ncu->ncu_if.nwamd_if_list;

        for (nifap = nifa; nifap != NULL; nifap = nifap->next)
                if (af == AF_UNSPEC || nifap->family == af)
                        nifap->configured = B_FALSE;
}

static void
dhcp_release(const char *ifname)
{
        ipadm_addr_info_t *ainfo, *ainfop;

        if (ipadm_addr_info(ipadm_handle, ifname, &ainfo, 0, 0)
            != IPADM_SUCCESS)
                return;

        for (ainfop = ainfo; ainfop != NULL; ainfop = IA_NEXT(ainfop)) {
                if (ainfop->ia_atype == IPADM_ADDR_DHCP)
                        nwamd_down_interface(ainfop->ia_aobjname,
                            ainfop->ia_atype, ifname);
        }
        ipadm_free_addr_info(ainfo);
}

static void
nwamd_plumb_unplumb_interface(nwamd_ncu_t *ncu, sa_family_t af, boolean_t plumb)
{
        char *ifname = ncu->ncu_name;
        nwamd_if_t *u_if = &ncu->ncu_if;
        ipadm_status_t ipstatus;

        nlog(LOG_DEBUG, "nwamd_plumb_unplumb_interface: %s %s %s",
            (plumb ? "plumb" : "unplumb"), (af == AF_INET ? "IPv4" : "IPv6"),
            ifname);

        if (plumb) {
                ipstatus = ipadm_create_if(ipadm_handle, ifname, af,
                    IPADM_OPT_ACTIVE);
        } else {
                /* release DHCP address, if any */
                if (af == AF_INET)
                        dhcp_release(ifname);
                ipstatus = ipadm_delete_if(ipadm_handle, ifname, af,
                    IPADM_OPT_ACTIVE);
        }

        if (ipstatus != IPADM_SUCCESS) {
                if ((plumb && ipstatus != IPADM_IF_EXISTS) ||
                    (!plumb && ipstatus != IPADM_ENXIO)) {
                        nlog(LOG_ERR, "nwamd_plumb_unplumb_interface: "
                            "%s %s failed for %s: %s",
                            (plumb ? "plumb" : "unplumb"),
                            (af == AF_INET ? "IPv4" : "IPv6"),
                            ifname, ipadm_status2str(ipstatus));
                }
        }

        /* Unset flags */
        if (!plumb) {
                unconfigure_addresses(ncu, af);
                switch (af) {
                case AF_INET:
                        u_if->nwamd_if_dhcp_configured = B_FALSE;
                        break;
                case AF_INET6:
                        u_if->nwamd_if_stateful_configured = B_FALSE;
                        u_if->nwamd_if_stateless_configured = B_FALSE;
                        break;
                }
        }
}

void
nwamd_plumb_interface(nwamd_ncu_t *ncu, sa_family_t af)
{
        /*
         * We get all posssible privs by calling nwamd_deescalate().  During
         * startup opening /dev/dld (data link management) needs all privs
         * because we don't have access to /etc/security/device_policy yet.
         */
        nwamd_escalate();
        nwamd_plumb_unplumb_interface(ncu, af, B_TRUE);
        nwamd_deescalate();
}

void
nwamd_unplumb_interface(nwamd_ncu_t *ncu, sa_family_t af)
{
        nwamd_plumb_unplumb_interface(ncu, af, B_FALSE);
}

static void *
start_dhcp_thread(void *arg)
{
        struct nwamd_dhcp_thread_arg *thread_arg = arg;
        nwamd_object_t ncu_obj;
        dhcp_ipc_type_t type;
        char *name;
        ipadm_addrobj_t ipaddr;
        ipadm_status_t ipstatus;
        int retries = 0;

        name = thread_arg->name;
        type = thread_arg->type;
        ipaddr = thread_arg->ipaddr;

retry:
        /* Make sure the NCU is in appropriate state for DHCP command */
        ncu_obj = nwamd_ncu_object_find(NWAM_NCU_TYPE_INTERFACE, name);
        if (ncu_obj == NULL) {
                nlog(LOG_ERR, "start_dhcp: no IP object %s", name);
                return (NULL);
        }

        if (ncu_obj->nwamd_object_state != NWAM_STATE_OFFLINE_TO_ONLINE &&
            ncu_obj->nwamd_object_state != NWAM_STATE_ONLINE) {
                nlog(LOG_INFO, "start_dhcp: IP NCU %s is in invalid state "
                    "for DHCP command", ncu_obj->nwamd_object_name);
                nwamd_object_release(ncu_obj);
                return (NULL);
        }
        nwamd_object_release(ncu_obj);

        switch (type) {
        case DHCP_INFORM:
        {
                char aobjname[IPADM_AOBJSIZ];

                if ((ipstatus = ipadm_get_aobjname(ipaddr, aobjname,
                    sizeof (aobjname))) != IPADM_SUCCESS) {
                        nlog(LOG_ERR, "start_dhcp: "
                            "ipadm_get_aobjname failed for %s: %s",
                            name, ipadm_status2str(ipstatus));
                        goto done;
                }
                ipstatus = ipadm_refresh_addr(ipadm_handle, aobjname,
                    IPADM_OPT_ACTIVE | IPADM_OPT_INFORM);
                break;
        }
        case DHCP_START:
                ipstatus = ipadm_create_addr(ipadm_handle, ipaddr,
                    IPADM_OPT_ACTIVE);
                break;
        default:
                nlog(LOG_ERR, "start_dhcp: invalid dhcp_ipc_type_t: %d", type);
                goto done;
        }

        if (ipstatus == IPADM_DHCP_IPC_TIMEOUT) {
                /*
                 * DHCP timed out: for DHCP_START requests, change state for
                 * this NCU and euqueue event to check NCU priority-groups;
                 * for DHCP_INFORM requests, nothing to do.
                 */
                if (type == DHCP_START) {
                        char *object_name;

                        nlog(LOG_INFO,
                            "start_dhcp: DHCP_START timed out for %s", name);

                        if (nwam_ncu_name_to_typed_name(name,
                            NWAM_NCU_TYPE_INTERFACE, &object_name)
                            != NWAM_SUCCESS) {
                                nlog(LOG_ERR, "start_dhcp: "
                                    "nwam_ncu_name_to_typed_name failed for %s",
                                    name);
                                goto done;
                        }
                        nwamd_object_set_state(NWAM_OBJECT_TYPE_NCU,
                            object_name, NWAM_STATE_OFFLINE_TO_ONLINE,
                            NWAM_AUX_STATE_IF_DHCP_TIMED_OUT);
                        nwamd_create_ncu_check_event(0);
                        free(object_name);
                } else {
                        nlog(LOG_INFO,
                            "start_dhcp: DHCP_INFORM timed out for %s", name);
                }

        } else if ((ipstatus == IPADM_DHCP_IPC_ERROR ||
            ipstatus == IPADM_IPC_ERROR) && retries++ < NWAMD_DHCP_RETRIES) {
                /*
                 * Retry DHCP request as we may have been unplumbing as part
                 * of the configuration phase.
                 */
                nlog(LOG_ERR, "start_dhcp: ipadm_%s_addr on %s returned: %s, "
                    "retrying in %d sec",
                    (type == DHCP_START ? "create" : "refresh"), name,
                    ipadm_status2str(ipstatus), NWAMD_DHCP_RETRY_WAIT_TIME);
                (void) sleep(NWAMD_DHCP_RETRY_WAIT_TIME);
                goto retry;

        } else if (ipstatus != IPADM_SUCCESS) {
                nlog(LOG_ERR, "start_dhcp: ipadm_%s_addr failed for %s: %s",
                    (type == DHCP_START ? "create" : "refresh"), name,
                    ipadm_status2str(ipstatus));
        }

done:
        free(name);
        free(arg);
        return (NULL);
}

static void
nwamd_dhcp(const char *ifname, ipadm_addrobj_t ipaddr, dhcp_ipc_type_t cmd)
{
        struct nwamd_dhcp_thread_arg *arg;
        pthread_attr_t attr;

        nlog(LOG_DEBUG, "nwamd_dhcp: starting DHCP %s thread for %s",
            dhcp_ipc_type_to_string(cmd), ifname);

        arg = malloc(sizeof (*arg));
        if (arg == NULL) {
                nlog(LOG_ERR, "nwamd_dhcp: error allocating memory for "
                    "dhcp request");
                return;
        }

        arg->name = strdup(ifname);
        arg->type = cmd;
        arg->ipaddr = ipaddr;

        (void) pthread_attr_init(&attr);
        (void) pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
        if (pthread_create(NULL, &attr, start_dhcp_thread, arg) == -1) {
                nlog(LOG_ERR, "nwamd_dhcp: cannot start dhcp thread");
                free(arg->name);
                free(arg);
                (void) pthread_attr_destroy(&attr);
                return;
        }
        (void) pthread_attr_destroy(&attr);
}