dhclient.c

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/*  $OpenBSD: dhclient.c,v 1.62 2004/12/05 18:35:51 deraadt Exp $   */

/*
 * Copyright 2004 Henning Brauer <henning@openbsd.org>
 * Copyright (c) 1995, 1996, 1997, 1998, 1999
 * The Internet Software Consortium.    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 Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM 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.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
 * Enterprises.  To learn more about the Internet Software Consortium,
 * see ``http://www.vix.com/isc''.  To learn more about Vixie
 * Enterprises, see ``http://www.vix.com''.
 *
 * This client was substantially modified and enhanced by Elliot Poger
 * for use on Linux while he was working on the MosquitoNet project at
 * Stanford.
 *
 * The current version owes much to Elliot's Linux enhancements, but
 * was substantially reorganized and partially rewritten by Ted Lemon
 * so as to use the same networking framework that the Internet Software
 * Consortium DHCP server uses.   Much system-specific configuration code
 * was moved into a shell script so that as support for more operating
 * systems is added, it will not be necessary to port and maintain
 * system-specific configuration code to these operating systems - instead,
 * the shell script can invoke the native tools to accomplish the same
 * purpose.
 */

#include <rosdhcp.h>

#define PERIOD 0x2e
#define hyphenchar(c) ((c) == 0x2d)
#define bslashchar(c) ((c) == 0x5c)
#define periodchar(c) ((c) == PERIOD)
#define asterchar(c) ((c) == 0x2a)
#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) || \
        ((c) >= 0x61 && (c) <= 0x7a))
#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)

#define borderchar(c) (alphachar(c) || digitchar(c))
#define middlechar(c) (borderchar(c) || hyphenchar(c))
#define domainchar(c) ((c) > 0x20 && (c) < 0x7f)

unsigned long debug_trace_level = 0; /* DEBUG_ULTRA */

char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
char *path_dhclient_db = NULL;

int log_perror = 1;
int privfd;
//int nullfd = -1;

struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
struct in_addr inaddr_any;
struct sockaddr_in sockaddr_broadcast;

/*
 * ASSERT_STATE() does nothing now; it used to be
 * assert (state_is == state_shouldbe).
 */
#define ASSERT_STATE(state_is, state_shouldbe) {}

#define TIME_MAX 2147483647

int     log_priority;
int     no_daemon;
int     unknown_ok = 1;
int     routefd;

void         usage(void);
int      check_option(struct client_lease *l, int option);
int      ipv4addrs(char * buf);
int      res_hnok(const char *dn);
char        *option_as_string(unsigned int code, unsigned char *data, int len);
int      fork_privchld(int, int);
int              check_arp( struct interface_info *ip, struct client_lease *lp );

#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))

time_t  scripttime;


int
init_client(void)
{
    ApiInit();
    AdapterInit();

    tzset();

    memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
    sockaddr_broadcast.sin_family = AF_INET;
    sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
    sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
    inaddr_any.s_addr = INADDR_ANY;
    bootp_packet_handler = do_packet;

    if (PipeInit() == INVALID_HANDLE_VALUE)
    {
        DbgPrint("DHCPCSVC: PipeInit() failed!\n");
        AdapterStop();
        ApiFree();
        return 0; // FALSE
    }

    return 1; // TRUE
}

void
stop_client(void)
{
    // AdapterStop();
    // ApiFree();
    /* FIXME: Close pipe and kill pipe thread */
}

/* XXX Implement me */
int check_arp( struct interface_info *ip, struct client_lease *lp ) {
    return 1;
}

/*
 * Individual States:
 *
 * Each routine is called from the dhclient_state_machine() in one of
 * these conditions:
 * -> entering INIT state
 * -> recvpacket_flag == 0: timeout in this state
 * -> otherwise: received a packet in this state
 *
 * Return conditions as handled by dhclient_state_machine():
 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
 * Returns 0: finish the nap which was interrupted for no good reason.
 *
 * Several per-interface variables are used to keep track of the process:
 *   active_lease: the lease that is being used on the interface
 *                 (null pointer if not configured yet).
 *   offered_leases: leases corresponding to DHCPOFFER messages that have
 *                   been sent to us by DHCP servers.
 *   acked_leases: leases corresponding to DHCPACK messages that have been
 *                 sent to us by DHCP servers.
 *   sendpacket: DHCP packet we're trying to send.
 *   destination: IP address to send sendpacket to
 * In addition, there are several relevant per-lease variables.
 *   T1_expiry, T2_expiry, lease_expiry: lease milestones
 * In the active lease, these control the process of renewing the lease;
 * In leases on the acked_leases list, this simply determines when we
 * can no longer legitimately use the lease.
 */

void
state_reboot(void *ipp)
{
    struct interface_info *ip = ipp;
    ULONG foo = (ULONG) GetTickCount();

    /* If we don't remember an active lease, go straight to INIT. */
    if (!ip->client->active || ip->client->active->is_bootp) {
        state_init(ip);
        return;
    }

    /* We are in the rebooting state. */
    ip->client->state = S_REBOOTING;

    /* make_request doesn't initialize xid because it normally comes
       from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
       so pick an xid now. */
    ip->client->xid = RtlRandom(&foo);

    /* Make a DHCPREQUEST packet, and set appropriate per-interface
       flags. */
    make_request(ip, ip->client->active);
    ip->client->destination = iaddr_broadcast;
    time(&ip->client->first_sending);
    ip->client->interval = ip->client->config->initial_interval;

    /* Zap the medium list... */
    ip->client->medium = NULL;

    /* Send out the first DHCPREQUEST packet. */
    send_request(ip);
}

/*
 * Called when a lease has completely expired and we've
 * been unable to renew it.
 */
void
state_init(void *ipp)
{
    struct interface_info *ip = ipp;

    ASSERT_STATE(state, S_INIT);

    /* Make a DHCPDISCOVER packet, and set appropriate per-interface
       flags. */
    make_discover(ip, ip->client->active);
    ip->client->xid = ip->client->packet.xid;
    ip->client->destination = iaddr_broadcast;
    ip->client->state = S_SELECTING;
    time(&ip->client->first_sending);
    ip->client->interval = ip->client->config->initial_interval;

    /* Add an immediate timeout to cause the first DHCPDISCOVER packet
       to go out. */
    send_discover(ip);
}

/*
 * state_selecting is called when one or more DHCPOFFER packets
 * have been received and a configurable period of time has passed.
 */
void
state_selecting(void *ipp)
{
    struct interface_info *ip = ipp;
    struct client_lease *lp, *next, *picked;
        time_t cur_time;

    ASSERT_STATE(state, S_SELECTING);

        time(&cur_time);

    /* Cancel state_selecting and send_discover timeouts, since either
       one could have got us here. */
    cancel_timeout(state_selecting, ip);
    cancel_timeout(send_discover, ip);

    /* We have received one or more DHCPOFFER packets.   Currently,
       the only criterion by which we judge leases is whether or
       not we get a response when we arp for them. */
    picked = NULL;
    for (lp = ip->client->offered_leases; lp; lp = next) {
        next = lp->next;

        /* Check to see if we got an ARPREPLY for the address
           in this particular lease. */
        if (!picked) {
                    if( !check_arp(ip,lp) ) goto freeit;
                    picked = lp;
                    picked->next = NULL;
        } else {
freeit:
            free_client_lease(lp);
        }
    }
    ip->client->offered_leases = NULL;

    /* If we just tossed all the leases we were offered, go back
       to square one. */
    if (!picked) {
        ip->client->state = S_INIT;
        state_init(ip);
        return;
    }

    /* If it was a BOOTREPLY, we can just take the address right now. */
    if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
        ip->client->new = picked;

        /* Make up some lease expiry times
           XXX these should be configurable. */
        ip->client->new->expiry = cur_time + 12000;
        ip->client->new->renewal += cur_time + 8000;
        ip->client->new->rebind += cur_time + 10000;

        ip->client->state = S_REQUESTING;

        /* Bind to the address we received. */
        bind_lease(ip);
        return;
    }

    /* Go to the REQUESTING state. */
    ip->client->destination = iaddr_broadcast;
    ip->client->state = S_REQUESTING;
    ip->client->first_sending = cur_time;
    ip->client->interval = ip->client->config->initial_interval;

    /* Make a DHCPREQUEST packet from the lease we picked. */
    make_request(ip, picked);
    ip->client->xid = ip->client->packet.xid;

    /* Toss the lease we picked - we'll get it back in a DHCPACK. */
    free_client_lease(picked);

    /* Add an immediate timeout to send the first DHCPREQUEST packet. */
    send_request(ip);
}

/* state_requesting is called when we receive a DHCPACK message after
   having sent out one or more DHCPREQUEST packets. */

void
dhcpack(struct packet *packet)
{
    struct interface_info *ip = packet->interface;
    struct client_lease *lease;
        time_t cur_time;

        time(&cur_time);

    /* If we're not receptive to an offer right now, or if the offer
       has an unrecognizable transaction id, then just drop it. */
    if (packet->interface->client->xid != packet->raw->xid ||
        (packet->interface->hw_address.hlen != packet->raw->hlen) ||
        (memcmp(packet->interface->hw_address.haddr,
        packet->raw->chaddr, packet->raw->hlen)))
        return;

    if (ip->client->state != S_REBOOTING &&
        ip->client->state != S_REQUESTING &&
        ip->client->state != S_RENEWING &&
        ip->client->state != S_REBINDING)
        return;

    note("DHCPACK from %s", piaddr(packet->client_addr));

    lease = packet_to_lease(packet);
    if (!lease) {
        note("packet_to_lease failed.");
        return;
    }

    ip->client->new = lease;

    /* Stop resending DHCPREQUEST. */
    cancel_timeout(send_request, ip);

    /* Figure out the lease time. */
    if (ip->client->new->options[DHO_DHCP_LEASE_TIME].data)
        ip->client->new->expiry = getULong(
            ip->client->new->options[DHO_DHCP_LEASE_TIME].data);
    else
        ip->client->new->expiry = DHCP_DEFAULT_LEASE_TIME;
    /* A number that looks negative here is really just very large,
       because the lease expiry offset is unsigned. */
    if (ip->client->new->expiry < 0)
        ip->client->new->expiry = TIME_MAX;
    /* XXX should be fixed by resetting the client state */
    if (ip->client->new->expiry < 60)
        ip->client->new->expiry = 60;

    /* Take the server-provided renewal time if there is one;
       otherwise figure it out according to the spec. */
    if (ip->client->new->options[DHO_DHCP_RENEWAL_TIME].len)
        ip->client->new->renewal = getULong(
            ip->client->new->options[DHO_DHCP_RENEWAL_TIME].data);
    else
        ip->client->new->renewal = ip->client->new->expiry / 2;

    /* Same deal with the rebind time. */
    if (ip->client->new->options[DHO_DHCP_REBINDING_TIME].len)
        ip->client->new->rebind = getULong(
            ip->client->new->options[DHO_DHCP_REBINDING_TIME].data);
    else
        ip->client->new->rebind = ip->client->new->renewal +
            ip->client->new->renewal / 2 + ip->client->new->renewal / 4;

#ifdef __REACTOS__
    ip->client->new->obtained = cur_time;
#endif
    ip->client->new->expiry += cur_time;
    /* Lease lengths can never be negative. */
    if (ip->client->new->expiry < cur_time)
        ip->client->new->expiry = TIME_MAX;
    ip->client->new->renewal += cur_time;
    if (ip->client->new->renewal < cur_time)
        ip->client->new->renewal = TIME_MAX;
    ip->client->new->rebind += cur_time;
    if (ip->client->new->rebind < cur_time)
        ip->client->new->rebind = TIME_MAX;

    bind_lease(ip);
}

void set_name_servers( PDHCP_ADAPTER Adapter, struct client_lease *new_lease ) {
    CHAR Buffer[200] = "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces\\";
    HKEY RegKey;

    strcat(Buffer, Adapter->DhclientInfo.name);
    if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, Buffer, 0, KEY_WRITE, &RegKey ) != ERROR_SUCCESS)
        return;


    if( new_lease->options[DHO_DOMAIN_NAME_SERVERS].len ) {

        struct iaddr nameserver;
        char *nsbuf;
        int i, addrs =
            new_lease->options[DHO_DOMAIN_NAME_SERVERS].len / sizeof(ULONG);

        nsbuf = malloc( addrs * sizeof(IP_ADDRESS_STRING) );

        if( nsbuf) {
            nsbuf[0] = 0;
            for( i = 0; i < addrs; i++ ) {
                nameserver.len = sizeof(ULONG);
                memcpy( nameserver.iabuf,
                        new_lease->options[DHO_DOMAIN_NAME_SERVERS].data +
                        (i * sizeof(ULONG)), sizeof(ULONG) );
                strcat( nsbuf, piaddr(nameserver) );
                if( i != addrs-1 ) strcat( nsbuf, "," );
            }

            DH_DbgPrint(MID_TRACE,("Setting DhcpNameserver: %s\n", nsbuf));

            RegSetValueExA( RegKey, "DhcpNameServer", 0, REG_SZ,
                           (LPBYTE)nsbuf, strlen(nsbuf) + 1 );
            free( nsbuf );
        }

    } else {
            RegDeleteValueW( RegKey, L"DhcpNameServer" );
    }

    RegCloseKey( RegKey );

}

void
set_domain(PDHCP_ADAPTER Adapter,
           struct client_lease *new_lease)
{
    CHAR Buffer1[MAX_PATH] = "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces\\";
    CHAR Buffer2[MAX_PATH] = "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters";
    HKEY RegKey1, RegKey2;

    strcat(Buffer1, Adapter->DhclientInfo.name);

    if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, Buffer1, 0, KEY_WRITE, &RegKey1 ) != ERROR_SUCCESS)
    {
        return;
    }

    if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, Buffer2, 0, KEY_WRITE, &RegKey2 ) != ERROR_SUCCESS)
    {
        RegCloseKey(RegKey1);
        return;
    }

    if (new_lease->options[DHO_DOMAIN_NAME].len)
    {
        DH_DbgPrint(MID_TRACE, ("Setting DhcpDomain: %s\n", new_lease->options[DHO_DOMAIN_NAME].data));

        RegSetValueExA(RegKey1,
                       "DhcpDomain",
                       0,
                       REG_SZ,
                       (LPBYTE)new_lease->options[DHO_DOMAIN_NAME].data,
                       new_lease->options[DHO_DOMAIN_NAME].len);

        RegSetValueExA(RegKey2,
                       "DhcpDomain",
                       0,
                       REG_SZ,
                       (LPBYTE)new_lease->options[DHO_DOMAIN_NAME].data,
                       new_lease->options[DHO_DOMAIN_NAME].len);
    }
    else
    {
        RegDeleteValueW(RegKey1, L"DhcpDomain");
        RegDeleteValueW(RegKey2, L"DhcpDomain");
    }

    RegCloseKey(RegKey1);
    RegCloseKey(RegKey2);

}

void setup_adapter( PDHCP_ADAPTER Adapter, struct client_lease *new_lease ) {
    CHAR Buffer[200] = "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces\\";
    struct iaddr netmask;
    HKEY hkey;
    int i;
    DWORD dwEnableDHCP;

    strcat(Buffer, Adapter->DhclientInfo.name);
    if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, Buffer, 0, KEY_WRITE, &hkey) != ERROR_SUCCESS)
        hkey = NULL;


    if( Adapter->NteContext )
    {
        DeleteIPAddress( Adapter->NteContext );
        Adapter->NteContext = 0;
    }

    /* Set up our default router if we got one from the DHCP server */
    if( new_lease->options[DHO_SUBNET_MASK].len ) {
        NTSTATUS Status;

        memcpy( netmask.iabuf,
                new_lease->options[DHO_SUBNET_MASK].data,
                new_lease->options[DHO_SUBNET_MASK].len );
        Status = AddIPAddress
            ( *((ULONG*)new_lease->address.iabuf),
              *((ULONG*)netmask.iabuf),
              Adapter->IfMib.dwIndex,
              &Adapter->NteContext,
              &Adapter->NteInstance );
        if (hkey) {
            RegSetValueExA(hkey, "DhcpIPAddress", 0, REG_SZ, (LPBYTE)piaddr(new_lease->address), strlen(piaddr(new_lease->address))+1);
            Buffer[0] = '\0';
            for(i = 0; i < new_lease->options[DHO_SUBNET_MASK].len; i++)
            {
                sprintf(&Buffer[strlen(Buffer)], "%u", new_lease->options[DHO_SUBNET_MASK].data[i]);
                if (i + 1 < new_lease->options[DHO_SUBNET_MASK].len)
                    strcat(Buffer, ".");
            }
            RegSetValueExA(hkey, "DhcpSubnetMask", 0, REG_SZ, (LPBYTE)Buffer, strlen(Buffer)+1);
            dwEnableDHCP = 1;
            RegSetValueExA(hkey, "EnableDHCP", 0, REG_DWORD, (LPBYTE)&dwEnableDHCP, sizeof(DWORD));
        }

        if( !NT_SUCCESS(Status) )
            warning("AddIPAddress: %lx\n", Status);
    }

    if( new_lease->options[DHO_ROUTERS].len ) {
        NTSTATUS Status;

        Adapter->RouterMib.dwForwardDest = 0; /* Default route */
        Adapter->RouterMib.dwForwardMask = 0;
        Adapter->RouterMib.dwForwardMetric1 = 1;
        Adapter->RouterMib.dwForwardIfIndex = Adapter->IfMib.dwIndex;

        if( Adapter->RouterMib.dwForwardNextHop ) {
            /* If we set a default route before, delete it before continuing */
            DeleteIpForwardEntry( &Adapter->RouterMib );
        }

        Adapter->RouterMib.dwForwardNextHop =
            *((ULONG*)new_lease->options[DHO_ROUTERS].data);

        Status = CreateIpForwardEntry( &Adapter->RouterMib );

        if( !NT_SUCCESS(Status) )
            warning("CreateIpForwardEntry: %lx\n", Status);

        if (hkey) {
            Buffer[0] = '\0';
            for(i = 0; i < new_lease->options[DHO_ROUTERS].len; i++)
            {
                sprintf(&Buffer[strlen(Buffer)], "%u", new_lease->options[DHO_ROUTERS].data[i]);
                if (i + 1 < new_lease->options[DHO_ROUTERS].len)
                    strcat(Buffer, ".");
            }
            RegSetValueExA(hkey, "DhcpDefaultGateway", 0, REG_SZ, (LPBYTE)Buffer, strlen(Buffer)+1);
        }
    }

    if (hkey)
        RegCloseKey(hkey);
}


void
bind_lease(struct interface_info *ip)
{
    PDHCP_ADAPTER Adapter;
    struct client_lease *new_lease = ip->client->new;
    time_t cur_time;

    time(&cur_time);

    /* Remember the medium. */
    ip->client->new->medium = ip->client->medium;

    /* Replace the old active lease with the new one. */
    if (ip->client->active)
        free_client_lease(ip->client->active);
    ip->client->active = ip->client->new;
    ip->client->new = NULL;

    /* Set up a timeout to start the renewal process. */
    /* Timeout of zero means no timeout (some implementations seem to use
     * one day).
     */
    if( ip->client->active->renewal - cur_time )
        add_timeout(ip->client->active->renewal, state_bound, ip);

    note("bound to %s -- renewal in %ld seconds.",
         piaddr(ip->client->active->address),
         (long int)(ip->client->active->renewal - cur_time));

    ip->client->state = S_BOUND;

    Adapter = AdapterFindInfo( ip );

    if( Adapter )  setup_adapter( Adapter, new_lease );
    else {
        warning("Could not find adapter for info %p\n", ip);
        return;
    }
    set_name_servers( Adapter, new_lease );
    set_domain( Adapter, new_lease );
}

/*
 * state_bound is called when we've successfully bound to a particular
 * lease, but the renewal time on that lease has expired.   We are
 * expected to unicast a DHCPREQUEST to the server that gave us our
 * original lease.
 */
void
state_bound(void *ipp)
{
    struct interface_info *ip = ipp;

    ASSERT_STATE(state, S_BOUND);

    /* T1 has expired. */
    make_request(ip, ip->client->active);
    ip->client->xid = ip->client->packet.xid;

    if (ip->client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
        memcpy(ip->client->destination.iabuf, ip->client->active->
            options[DHO_DHCP_SERVER_IDENTIFIER].data, 4);
        ip->client->destination.len = 4;
    } else
        ip->client->destination = iaddr_broadcast;

    time(&ip->client->first_sending);
    ip->client->interval = ip->client->config->initial_interval;
    ip->client->state = S_RENEWING;

    /* Send the first packet immediately. */
    send_request(ip);
}

void
bootp(struct packet *packet)
{
    struct iaddrlist *ap;

    if (packet->raw->op != BOOTREPLY)
        return;

    /* If there's a reject list, make sure this packet's sender isn't
       on it. */
    for (ap = packet->interface->client->config->reject_list;
        ap; ap = ap->next) {
        if (addr_eq(packet->client_addr, ap->addr)) {
            note("BOOTREPLY from %s rejected.", piaddr(ap->addr));
            return;
        }
    }
    dhcpoffer(packet);
}

void
dhcp(struct packet *packet)
{
    struct iaddrlist *ap;
    void (*handler)(struct packet *);
    char *type;

    switch (packet->packet_type) {
    case DHCPOFFER:
        handler = dhcpoffer;
        type = "DHCPOFFER";
        break;
    case DHCPNAK:
        handler = dhcpnak;
        type = "DHCPNACK";
        break;
    case DHCPACK:
        handler = dhcpack;
        type = "DHCPACK";
        break;
    default:
        return;
    }

    /* If there's a reject list, make sure this packet's sender isn't
       on it. */
    for (ap = packet->interface->client->config->reject_list;
        ap; ap = ap->next) {
        if (addr_eq(packet->client_addr, ap->addr)) {
            note("%s from %s rejected.", type, piaddr(ap->addr));
            return;
        }
    }
    (*handler)(packet);
}

void
dhcpoffer(struct packet *packet)
{
    struct interface_info *ip = packet->interface;
    struct client_lease *lease, *lp;
    int i;
    int arp_timeout_needed = 0, stop_selecting;
    char *name = packet->options[DHO_DHCP_MESSAGE_TYPE].len ?
        "DHCPOFFER" : "BOOTREPLY";
        time_t cur_time;

        time(&cur_time);

    /* If we're not receptive to an offer right now, or if the offer
       has an unrecognizable transaction id, then just drop it. */
    if (ip->client->state != S_SELECTING ||
            packet->interface->client->xid != packet->raw->xid ||
            (packet->interface->hw_address.hlen != packet->raw->hlen) ||
        (memcmp(packet->interface->hw_address.haddr,
        packet->raw->chaddr, packet->raw->hlen)))
        return;

    note("%s from %s", name, piaddr(packet->client_addr));


    /* If this lease doesn't supply the minimum required parameters,
       blow it off. */
    for (i = 0; ip->client->config->required_options[i]; i++) {
        if (!packet->options[ip->client->config->
            required_options[i]].len) {
            note("%s isn't satisfactory.", name);
            return;
        }
    }

    /* If we've already seen this lease, don't record it again. */
    for (lease = ip->client->offered_leases;
        lease; lease = lease->next) {
        if (lease->address.len == sizeof(packet->raw->yiaddr) &&
            !memcmp(lease->address.iabuf,
            &packet->raw->yiaddr, lease->address.len)) {
            debug("%s already seen.", name);
            return;
        }
    }

    lease = packet_to_lease(packet);
    if (!lease) {
        note("packet_to_lease failed.");
        return;
    }

    /* If this lease was acquired through a BOOTREPLY, record that
       fact. */
    if (!packet->options[DHO_DHCP_MESSAGE_TYPE].len)
        lease->is_bootp = 1;

    /* Record the medium under which this lease was offered. */
    lease->medium = ip->client->medium;

    /* Send out an ARP Request for the offered IP address. */
        if( !check_arp( ip, lease ) ) {
            note("Arp check failed\n");
            return;
        }

    /* Figure out when we're supposed to stop selecting. */
    stop_selecting =
        ip->client->first_sending + ip->client->config->select_interval;

    /* If this is the lease we asked for, put it at the head of the
       list, and don't mess with the arp request timeout. */
    if (lease->address.len == ip->client->requested_address.len &&
        !memcmp(lease->address.iabuf,
        ip->client->requested_address.iabuf,
        ip->client->requested_address.len)) {
        lease->next = ip->client->offered_leases;
        ip->client->offered_leases = lease;
    } else {
        /* If we already have an offer, and arping for this
           offer would take us past the selection timeout,
           then don't extend the timeout - just hope for the
           best. */
        if (ip->client->offered_leases &&
            (cur_time + arp_timeout_needed) > stop_selecting)
            arp_timeout_needed = 0;

        /* Put the lease at the end of the list. */
        lease->next = NULL;
        if (!ip->client->offered_leases)
            ip->client->offered_leases = lease;
        else {
            for (lp = ip->client->offered_leases; lp->next;
                lp = lp->next)
                ;   /* nothing */
            lp->next = lease;
        }
    }

    /* If we're supposed to stop selecting before we've had time
       to wait for the ARPREPLY, add some delay to wait for
       the ARPREPLY. */
    if (stop_selecting - cur_time < arp_timeout_needed)
        stop_selecting = cur_time + arp_timeout_needed;

    /* If the selecting interval has expired, go immediately to
       state_selecting().  Otherwise, time out into
       state_selecting at the select interval. */
    if (stop_selecting <= 0)
        state_selecting(ip);
    else {
        add_timeout(stop_selecting, state_selecting, ip);
        cancel_timeout(send_discover, ip);
    }
}

/* Allocate a client_lease structure and initialize it from the parameters
   in the specified packet. */

struct client_lease *
packet_to_lease(struct packet *packet)
{
    struct client_lease *lease;
    int i;

    lease = malloc(sizeof(struct client_lease));

    if (!lease) {
        warning("dhcpoffer: no memory to record lease.");
        return (NULL);
    }

    memset(lease, 0, sizeof(*lease));

    /* Copy the lease options. */
    for (i = 0; i < 256; i++) {
        if (packet->options[i].len) {
            lease->options[i].data =
                malloc(packet->options[i].len + 1);
            if (!lease->options[i].data) {
                warning("dhcpoffer: no memory for option %d", i);
                free_client_lease(lease);
                return (NULL);
            } else {
                memcpy(lease->options[i].data,
                    packet->options[i].data,
                    packet->options[i].len);
                lease->options[i].len =
                    packet->options[i].len;
                lease->options[i].data[lease->options[i].len] =
                    0;
            }
            if (!check_option(lease,i)) {
                /* ignore a bogus lease offer */
                warning("Invalid lease option - ignoring offer");
                free_client_lease(lease);
                return (NULL);
            }
        }
    }

    lease->address.len = sizeof(packet->raw->yiaddr);
    memcpy(lease->address.iabuf, &packet->raw->yiaddr, lease->address.len);
#ifdef __REACTOS__
    lease->serveraddress.len = sizeof(packet->raw->siaddr);
    memcpy(lease->serveraddress.iabuf, &packet->raw->siaddr, lease->address.len);
#endif

    /* If the server name was filled out, copy it. */
    if ((!packet->options[DHO_DHCP_OPTION_OVERLOAD].len ||
        !(packet->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
        packet->raw->sname[0]) {
        lease->server_name = malloc(DHCP_SNAME_LEN + 1);
        if (!lease->server_name) {
            warning("dhcpoffer: no memory for server name.");
            free_client_lease(lease);
            return (NULL);
        }
        memcpy(lease->server_name, packet->raw->sname, DHCP_SNAME_LEN);
        lease->server_name[DHCP_SNAME_LEN]='\0';
        if (!res_hnok(lease->server_name) ) {
            warning("Bogus server name %s",  lease->server_name );
            free_client_lease(lease);
            return (NULL);
        }

    }

    /* Ditto for the filename. */
    if ((!packet->options[DHO_DHCP_OPTION_OVERLOAD].len ||
        !(packet->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
        packet->raw->file[0]) {
        /* Don't count on the NUL terminator. */
        lease->filename = malloc(DHCP_FILE_LEN + 1);
        if (!lease->filename) {
            warning("dhcpoffer: no memory for filename.");
            free_client_lease(lease);
            return (NULL);
        }
        memcpy(lease->filename, packet->raw->file, DHCP_FILE_LEN);
        lease->filename[DHCP_FILE_LEN]='\0';
    }
    return lease;
}

void
dhcpnak(struct packet *packet)
{
    struct interface_info *ip = packet->interface;

    /* If we're not receptive to an offer right now, or if the offer
       has an unrecognizable transaction id, then just drop it. */
    if (packet->interface->client->xid != packet->raw->xid ||
        (packet->interface->hw_address.hlen != packet->raw->hlen) ||
        (memcmp(packet->interface->hw_address.haddr,
        packet->raw->chaddr, packet->raw->hlen)))
        return;

    if (ip->client->state != S_REBOOTING &&
        ip->client->state != S_REQUESTING &&
        ip->client->state != S_RENEWING &&
        ip->client->state != S_REBINDING)
        return;

    note("DHCPNAK from %s", piaddr(packet->client_addr));

    if (!ip->client->active) {
        note("DHCPNAK with no active lease.\n");
        return;
    }

    free_client_lease(ip->client->active);
    ip->client->active = NULL;

    /* Stop sending DHCPREQUEST packets... */
    cancel_timeout(send_request, ip);

    ip->client->state = S_INIT;
    state_init(ip);
}

/* Send out a DHCPDISCOVER packet, and set a timeout to send out another
   one after the right interval has expired.  If we don't get an offer by
   the time we reach the panic interval, call the panic function. */

void
send_discover(void *ipp)
{
    struct interface_info *ip = ipp;
    int interval, increase = 1;
        time_t cur_time;

        DH_DbgPrint(MID_TRACE,("Doing discover on interface %p\n",ip));

        time(&cur_time);

    /* Figure out how long it's been since we started transmitting. */
    interval = cur_time - ip->client->first_sending;

    /* If we're past the panic timeout, call the script and tell it
       we haven't found anything for this interface yet. */
    if (interval > ip->client->config->timeout) {
        state_panic(ip);
        ip->client->first_sending = cur_time;
    }

    /* If we're selecting media, try the whole list before doing
       the exponential backoff, but if we've already received an
       offer, stop looping, because we obviously have it right. */
    if (!ip->client->offered_leases &&
        ip->client->config->media) {
        int fail = 0;

        if (ip->client->medium) {
            ip->client->medium = ip->client->medium->next;
            increase = 0;
        }
        if (!ip->client->medium) {
            if (fail)
                error("No valid media types for %s!", ip->name);
            ip->client->medium = ip->client->config->media;
            increase = 1;
        }

        note("Trying medium \"%s\" %d", ip->client->medium->string,
            increase);
                /* XXX Support other media types eventually */
    }

    /*
     * If we're supposed to increase the interval, do so.  If it's
     * currently zero (i.e., we haven't sent any packets yet), set
     * it to one; otherwise, add to it a random number between zero
     * and two times itself.  On average, this means that it will
     * double with every transmission.
     */
    if (increase) {
        if (!ip->client->interval)
            ip->client->interval =
                ip->client->config->initial_interval;
        else {
            ip->client->interval += (rand() >> 2) %
                (2 * ip->client->interval);
        }

        /* Don't backoff past cutoff. */
        if (ip->client->interval >
            ip->client->config->backoff_cutoff)
            ip->client->interval =
                ((ip->client->config->backoff_cutoff / 2)
                 + ((rand() >> 2) %
                    ip->client->config->backoff_cutoff));
    } else if (!ip->client->interval)
        ip->client->interval =
            ip->client->config->initial_interval;

    /* If the backoff would take us to the panic timeout, just use that
       as the interval. */
    if (cur_time + ip->client->interval >
        ip->client->first_sending + ip->client->config->timeout)
        ip->client->interval =
            (ip->client->first_sending +
             ip->client->config->timeout) - cur_time + 1;

    /* Record the number of seconds since we started sending. */
    if (interval < 65536)
        ip->client->packet.secs = htons(interval);
    else
        ip->client->packet.secs = htons(65535);
    ip->client->secs = ip->client->packet.secs;

    note("DHCPDISCOVER on %s to %s port %d interval %ld",
        ip->name, inet_ntoa(sockaddr_broadcast.sin_addr),
        ntohs(sockaddr_broadcast.sin_port), (long int)ip->client->interval);

    /* Send out a packet. */
    (void)send_packet(ip, &ip->client->packet, ip->client->packet_length,
        inaddr_any, &sockaddr_broadcast, NULL);

        DH_DbgPrint(MID_TRACE,("discover timeout: now %x -> then %x\n",
                               cur_time, cur_time + ip->client->interval));

    add_timeout(cur_time + ip->client->interval, send_discover, ip);
}

/*
 * state_panic gets called if we haven't received any offers in a preset
 * amount of time.   When this happens, we try to use existing leases
 * that haven't yet expired, and failing that, we call the client script
 * and hope it can do something.
 */
void
state_panic(void *ipp)
{
    struct interface_info *ip = ipp;
        PDHCP_ADAPTER Adapter = AdapterFindInfo(ip);

    note("No DHCPOFFERS received.");

        if (!Adapter->NteContext)
        {
            /* Generate an automatic private address */
            DbgPrint("DHCPCSVC: Failed to receive a response from a DHCP server. An automatic private address will be assigned.\n");

            /* FIXME: The address generation code sucks */
            AddIPAddress(htonl(0xA9FE0000 | (rand() % 0xFFFF)), //169.254.X.X
                         htonl(0xFFFF0000), //255.255.0.0
                         Adapter->IfMib.dwIndex,
                         &Adapter->NteContext,
                         &Adapter->NteInstance);
        }
}

void
send_request(void *ipp)
{
    struct interface_info *ip = ipp;
    struct sockaddr_in destination;
    struct in_addr from;
    int interval;
        time_t cur_time;

        time(&cur_time); 

    /* Figure out how long it's been since we started transmitting. */
    interval = cur_time - ip->client->first_sending;

    /* If we're in the INIT-REBOOT or REQUESTING state and we're
       past the reboot timeout, go to INIT and see if we can
       DISCOVER an address... */
    /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
       means either that we're on a network with no DHCP server,
       or that our server is down.  In the latter case, assuming
       that there is a backup DHCP server, DHCPDISCOVER will get
       us a new address, but we could also have successfully
       reused our old address.  In the former case, we're hosed
       anyway.  This is not a win-prone situation. */
    if ((ip->client->state == S_REBOOTING ||
        ip->client->state == S_REQUESTING) &&
        interval > ip->client->config->reboot_timeout) {
        ip->client->state = S_INIT;
        cancel_timeout(send_request, ip);
        state_init(ip);
        return;
    }

    /* If we're in the reboot state, make sure the media is set up
       correctly. */
    if (ip->client->state == S_REBOOTING &&
        !ip->client->medium &&
        ip->client->active->medium ) {
        /* If the medium we chose won't fly, go to INIT state. */
                /* XXX Nothing for now */

        /* Record the medium. */
        ip->client->medium = ip->client->active->medium;
    }

    /* If the lease has expired, relinquish the address and go back
       to the INIT state. */
    if (ip->client->state != S_REQUESTING &&
        cur_time > ip->client->active->expiry) {
            PDHCP_ADAPTER Adapter = AdapterFindInfo( ip );
            /* Run the client script with the new parameters. */
            /* No script actions necessary in the expiry case */
            /* Now do a preinit on the interface so that we can
               discover a new address. */

            if( Adapter )
            {
                DeleteIPAddress( Adapter->NteContext );
                Adapter->NteContext = 0;
            }

            ip->client->state = S_INIT;
            state_init(ip);
            return;
    }

    /* Do the exponential backoff... */
    if (!ip->client->interval)
        ip->client->interval = ip->client->config->initial_interval;
    else
        ip->client->interval += ((rand() >> 2) %
            (2 * ip->client->interval));

    /* Don't backoff past cutoff. */
    if (ip->client->interval >
        ip->client->config->backoff_cutoff)
        ip->client->interval =
            ((ip->client->config->backoff_cutoff / 2) +
            ((rand() >> 2) % ip->client->interval));

    /* If the backoff would take us to the expiry time, just set the
       timeout to the expiry time. */
    if (ip->client->state != S_REQUESTING &&
        cur_time + ip->client->interval >
        ip->client->active->expiry)
        ip->client->interval =
            ip->client->active->expiry - cur_time + 1;

    /* If the lease T2 time has elapsed, or if we're not yet bound,
       broadcast the DHCPREQUEST rather than unicasting. */
    memset(&destination, 0, sizeof(destination));
    if (ip->client->state == S_REQUESTING ||
        ip->client->state == S_REBOOTING ||
        cur_time > ip->client->active->rebind)
        destination.sin_addr.s_addr = INADDR_BROADCAST;
    else
        memcpy(&destination.sin_addr.s_addr,
            ip->client->destination.iabuf,
            sizeof(destination.sin_addr.s_addr));
    destination.sin_port = htons(REMOTE_PORT);
    destination.sin_family = AF_INET;
//  destination.sin_len = sizeof(destination);

    if (ip->client->state != S_REQUESTING)
        memcpy(&from, ip->client->active->address.iabuf,
            sizeof(from));
    else
        from.s_addr = INADDR_ANY;

    /* Record the number of seconds since we started sending. */
    if (ip->client->state == S_REQUESTING)
        ip->client->packet.secs = ip->client->secs;
    else {
        if (interval < 65536)
            ip->client->packet.secs = htons(interval);
        else
            ip->client->packet.secs = htons(65535);
    }

    note("DHCPREQUEST on %s to %s port %d", ip->name,
        inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));

    /* Send out a packet. */
    (void) send_packet(ip, &ip->client->packet, ip->client->packet_length,
        from, &destination, NULL);

    add_timeout(cur_time + ip->client->interval, send_request, ip);
}

void
send_decline(void *ipp)
{
    struct interface_info *ip = ipp;

    note("DHCPDECLINE on %s to %s port %d", ip->name,
        inet_ntoa(sockaddr_broadcast.sin_addr),
        ntohs(sockaddr_broadcast.sin_port));

    /* Send out a packet. */
    (void) send_packet(ip, &ip->client->packet, ip->client->packet_length,
        inaddr_any, &sockaddr_broadcast, NULL);
}

void
make_discover(struct interface_info *ip, struct client_lease *lease)
{
    unsigned char discover = DHCPDISCOVER;
    struct tree_cache *options[256];
    struct tree_cache option_elements[256];
    int i;
    ULONG foo = (ULONG) GetTickCount();

    memset(option_elements, 0, sizeof(option_elements));
    memset(options, 0, sizeof(options));
    memset(&ip->client->packet, 0, sizeof(ip->client->packet));

    /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
    i = DHO_DHCP_MESSAGE_TYPE;
    options[i] = &option_elements[i];
    options[i]->value = &discover;
    options[i]->len = sizeof(discover);
    options[i]->buf_size = sizeof(discover);
    options[i]->timeout = 0xFFFFFFFF;

    /* Request the options we want */
    i  = DHO_DHCP_PARAMETER_REQUEST_LIST;
    options[i] = &option_elements[i];
    options[i]->value = ip->client->config->requested_options;
    options[i]->len = ip->client->config->requested_option_count;
    options[i]->buf_size =
        ip->client->config->requested_option_count;
    options[i]->timeout = 0xFFFFFFFF;

    /* If we had an address, try to get it again. */
    if (lease) {
        ip->client->requested_address = lease->address;
        i = DHO_DHCP_REQUESTED_ADDRESS;
        options[i] = &option_elements[i];
        options[i]->value = lease->address.iabuf;
        options[i]->len = lease->address.len;
        options[i]->buf_size = lease->address.len;
        options[i]->timeout = 0xFFFFFFFF;
    } else
        ip->client->requested_address.len = 0;

    /* Send any options requested in the config file. */
    for (i = 0; i < 256; i++)
        if (!options[i] &&
            ip->client->config->send_options[i].data) {
            options[i] = &option_elements[i];
            options[i]->value =
                ip->client->config->send_options[i].data;
            options[i]->len =
                ip->client->config->send_options[i].len;
            options[i]->buf_size =
                ip->client->config->send_options[i].len;
            options[i]->timeout = 0xFFFFFFFF;
        }

    /* Set up the option buffer... */
    ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
        options, 0, 0, 0, NULL, 0);
    if (ip->client->packet_length < BOOTP_MIN_LEN)
        ip->client->packet_length = BOOTP_MIN_LEN;

    ip->client->packet.op = BOOTREQUEST;
    ip->client->packet.htype = ip->hw_address.htype;
    ip->client->packet.hlen = ip->hw_address.hlen;
    ip->client->packet.hops = 0;
    ip->client->packet.xid = RtlRandom(&foo);
    ip->client->packet.secs = 0; /* filled in by send_discover. */
    ip->client->packet.flags = 0;

    memset(&(ip->client->packet.ciaddr),
        0, sizeof(ip->client->packet.ciaddr));
    memset(&(ip->client->packet.yiaddr),
        0, sizeof(ip->client->packet.yiaddr));
    memset(&(ip->client->packet.siaddr),
        0, sizeof(ip->client->packet.siaddr));
    memset(&(ip->client->packet.giaddr),
        0, sizeof(ip->client->packet.giaddr));
    memcpy(ip->client->packet.chaddr,
        ip->hw_address.haddr, ip->hw_address.hlen);
}


void
make_request(struct interface_info *ip, struct client_lease * lease)
{
    unsigned char request = DHCPREQUEST;
    struct tree_cache *options[256];
    struct tree_cache option_elements[256];
    int i;

    memset(options, 0, sizeof(options));
    memset(&ip->client->packet, 0, sizeof(ip->client->packet));

    /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
    i = DHO_DHCP_MESSAGE_TYPE;
    options[i] = &option_elements[i];
    options[i]->value = &request;
    options[i]->len = sizeof(request);
    options[i]->buf_size = sizeof(request);
    options[i]->timeout = 0xFFFFFFFF;

    /* Request the options we want */
    i = DHO_DHCP_PARAMETER_REQUEST_LIST;
    options[i] = &option_elements[i];
    options[i]->value = ip->client->config->requested_options;
    options[i]->len = ip->client->config->requested_option_count;
    options[i]->buf_size =
        ip->client->config->requested_option_count;
    options[i]->timeout = 0xFFFFFFFF;

    /* If we are requesting an address that hasn't yet been assigned
       to us, use the DHCP Requested Address option. */
    if (ip->client->state == S_REQUESTING) {
        /* Send back the server identifier... */
        i = DHO_DHCP_SERVER_IDENTIFIER;
        options[i] = &option_elements[i];
        options[i]->value = lease->options[i].data;
        options[i]->len = lease->options[i].len;
        options[i]->buf_size = lease->options[i].len;
        options[i]->timeout = 0xFFFFFFFF;
    }
    if (ip->client->state == S_REQUESTING ||
        ip->client->state == S_REBOOTING) {
        ip->client->requested_address = lease->address;
        i = DHO_DHCP_REQUESTED_ADDRESS;
        options[i] = &option_elements[i];
        options[i]->value = lease->address.iabuf;
        options[i]->len = lease->address.len;
        options[i]->buf_size = lease->address.len;
        options[i]->timeout = 0xFFFFFFFF;
    } else
        ip->client->requested_address.len = 0;

    /* Send any options requested in the config file. */
    for (i = 0; i < 256; i++)
        if (!options[i] &&
            ip->client->config->send_options[i].data) {
            options[i] = &option_elements[i];
            options[i]->value =
                ip->client->config->send_options[i].data;
            options[i]->len =
                ip->client->config->send_options[i].len;
            options[i]->buf_size =
                ip->client->config->send_options[i].len;
            options[i]->timeout = 0xFFFFFFFF;
        }

    /* Set up the option buffer... */
    ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
        options, 0, 0, 0, NULL, 0);
    if (ip->client->packet_length < BOOTP_MIN_LEN)
        ip->client->packet_length = BOOTP_MIN_LEN;

    ip->client->packet.op = BOOTREQUEST;
    ip->client->packet.htype = ip->hw_address.htype;
    ip->client->packet.hlen = ip->hw_address.hlen;
    ip->client->packet.hops = 0;
    ip->client->packet.xid = ip->client->xid;
    ip->client->packet.secs = 0; /* Filled in by send_request. */

    /* If we own the address we're requesting, put it in ciaddr;
       otherwise set ciaddr to zero. */
    if (ip->client->state == S_BOUND ||
        ip->client->state == S_RENEWING ||
        ip->client->state == S_REBINDING) {
        memcpy(&ip->client->packet.ciaddr,
            lease->address.iabuf, lease->address.len);
        ip->client->packet.flags = 0;
    } else {
        memset(&ip->client->packet.ciaddr, 0,
            sizeof(ip->client->packet.ciaddr));
        ip->client->packet.flags = 0;
    }

    memset(&ip->client->packet.yiaddr, 0,
        sizeof(ip->client->packet.yiaddr));
    memset(&ip->client->packet.siaddr, 0,
        sizeof(ip->client->packet.siaddr));
    memset(&ip->client->packet.giaddr, 0,
        sizeof(ip->client->packet.giaddr));
    memcpy(ip->client->packet.chaddr,
        ip->hw_address.haddr, ip->hw_address.hlen);
}

void
make_decline(struct interface_info *ip, struct client_lease *lease)
{
    struct tree_cache *options[256], message_type_tree;
    struct tree_cache requested_address_tree;
    struct tree_cache server_id_tree, client_id_tree;
    unsigned char decline = DHCPDECLINE;
    int i;

    memset(options, 0, sizeof(options));
    memset(&ip->client->packet, 0, sizeof(ip->client->packet));

    /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
    i = DHO_DHCP_MESSAGE_TYPE;
    options[i] = &message_type_tree;
    options[i]->value = &decline;
    options[i]->len = sizeof(decline);
    options[i]->buf_size = sizeof(decline);
    options[i]->timeout = 0xFFFFFFFF;

    /* Send back the server identifier... */
    i = DHO_DHCP_SERVER_IDENTIFIER;
    options[i] = &server_id_tree;
    options[i]->value = lease->options[i].data;
    options[i]->len = lease->options[i].len;
    options[i]->buf_size = lease->options[i].len;
    options[i]->timeout = 0xFFFFFFFF;

    /* Send back the address we're declining. */
    i = DHO_DHCP_REQUESTED_ADDRESS;
    options[i] = &requested_address_tree;
    options[i]->value = lease->address.iabuf;
    options[i]->len = lease->address.len;
    options[i]->buf_size = lease->address.len;
    options[i]->timeout = 0xFFFFFFFF;

    /* Send the uid if the user supplied one. */
    i = DHO_DHCP_CLIENT_IDENTIFIER;
    if (ip->client->config->send_options[i].len) {
        options[i] = &client_id_tree;
        options[i]->value = ip->client->config->send_options[i].data;
        options[i]->len = ip->client->config->send_options[i].len;
        options[i]->buf_size = ip->client->config->send_options[i].len;
        options[i]->timeout = 0xFFFFFFFF;
    }


    /* Set up the option buffer... */
    ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
        options, 0, 0, 0, NULL, 0);
    if (ip->client->packet_length < BOOTP_MIN_LEN)
        ip->client->packet_length = BOOTP_MIN_LEN;

    ip->client->packet.op = BOOTREQUEST;
    ip->client->packet.htype = ip->hw_address.htype;
    ip->client->packet.hlen = ip->hw_address.hlen;
    ip->client->packet.hops = 0;
    ip->client->packet.xid = ip->client->xid;
    ip->client->packet.secs = 0; /* Filled in by send_request. */
    ip->client->packet.flags = 0;

    /* ciaddr must always be zero. */
    memset(&ip->client->packet.ciaddr, 0,
        sizeof(ip->client->packet.ciaddr));
    memset(&ip->client->packet.yiaddr, 0,
        sizeof(ip->client->packet.yiaddr));
    memset(&ip->client->packet.siaddr, 0,
        sizeof(ip->client->packet.siaddr));
    memset(&ip->client->packet.giaddr, 0,
        sizeof(ip->client->packet.giaddr));
    memcpy(ip->client->packet.chaddr,
        ip->hw_address.haddr, ip->hw_address.hlen);
}

void
free_client_lease(struct client_lease *lease)
{
    int i;

    if (lease->server_name)
        free(lease->server_name);
    if (lease->filename)
        free(lease->filename);
    for (i = 0; i < 256; i++) {
        if (lease->options[i].len)
            free(lease->options[i].data);
    }
    free(lease);
}

FILE *leaseFile;

void
rewrite_client_leases(struct interface_info *ifi)
{
    struct client_lease *lp;

    if (!leaseFile) {
        leaseFile = fopen(path_dhclient_db, "w");
        if (!leaseFile)
            error("can't create %s", path_dhclient_db);
    } else {
        fflush(leaseFile);
        rewind(leaseFile);
    }

    for (lp = ifi->client->leases; lp; lp = lp->next)
        write_client_lease(ifi, lp, 1);
    if (ifi->client->active)
        write_client_lease(ifi, ifi->client->active, 1);

    fflush(leaseFile);
}

void
write_client_lease(struct interface_info *ip, struct client_lease *lease,
    int rewrite)
{
    static int leases_written;
    struct tm *t;
    int i;

    if (!rewrite) {
        if (leases_written++ > 20) {
            rewrite_client_leases(ip);
            leases_written = 0;
        }
    }

    /* If the lease came from the config file, we don't need to stash
       a copy in the lease database. */
    if (lease->is_static)
        return;

    if (!leaseFile) {   /* XXX */
        leaseFile = fopen(path_dhclient_db, "w");
        if (!leaseFile) {
            error("can't create %s", path_dhclient_db);
                        return;
                }
    }

    fprintf(leaseFile, "lease {\n");
    if (lease->is_bootp)
        fprintf(leaseFile, "  bootp;\n");
    fprintf(leaseFile, "  interface \"%s\";\n", ip->name);
    fprintf(leaseFile, "  fixed-address %s;\n", piaddr(lease->address));
    if (lease->filename)
        fprintf(leaseFile, "  filename \"%s\";\n", lease->filename);
    if (lease->server_name)
        fprintf(leaseFile, "  server-name \"%s\";\n",
            lease->server_name);
    if (lease->medium)
        fprintf(leaseFile, "  medium \"%s\";\n", lease->medium->string);
    for (i = 0; i < 256; i++)
        if (lease->options[i].len)
            fprintf(leaseFile, "  option %s %s;\n",
                dhcp_options[i].name,
                pretty_print_option(i, lease->options[i].data,
                lease->options[i].len, 1, 1));

    t = gmtime(&lease->renewal);
        if (t)
        fprintf(leaseFile, "  renew %d %d/%d/%d %02d:%02d:%02d;\n",
            t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
            t->tm_hour, t->tm_min, t->tm_sec);
    t = gmtime(&lease->rebind);
        if (t)
        fprintf(leaseFile, "  rebind %d %d/%d/%d %02d:%02d:%02d;\n",
             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
             t->tm_hour, t->tm_min, t->tm_sec);
    t = gmtime(&lease->expiry);
        if (t)
        fprintf(leaseFile, "  expire %d %d/%d/%d %02d:%02d:%02d;\n",
            t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
            t->tm_hour, t->tm_min, t->tm_sec);
    fprintf(leaseFile, "}\n");
    fflush(leaseFile);
}

void
priv_script_init(struct interface_info *ip, char *reason, char *medium)
{
    if (ip) {
            // XXX Do we need to do anything?
        }
}

void
priv_script_write_params(struct interface_info *ip, char *prefix, struct client_lease *lease)
{
    u_int8_t dbuf[1500];
    int i, len = 0;

#if 0
    script_set_env(ip->client, prefix, "ip_address",
        piaddr(lease->address));
#endif

    if (lease->options[DHO_SUBNET_MASK].len &&
        (lease->options[DHO_SUBNET_MASK].len <
        sizeof(lease->address.iabuf))) {
        struct iaddr netmask, subnet, broadcast;

        memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
            lease->options[DHO_SUBNET_MASK].len);
        netmask.len = lease->options[DHO_SUBNET_MASK].len;

        subnet = subnet_number(lease->address, netmask);
        if (subnet.len) {
#if 0
            script_set_env(ip->client, prefix, "network_number",
                piaddr(subnet));
#endif
            if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
                broadcast = broadcast_addr(subnet, netmask);
                if (broadcast.len)
#if 0
                    script_set_env(ip->client, prefix,
                        "broadcast_address",
                        piaddr(broadcast));
#else
                                ;
#endif
            }
        }
    }

#if 0
    if (lease->filename)
        script_set_env(ip->client, prefix, "filename", lease->filename);
    if (lease->server_name)
        script_set_env(ip->client, prefix, "server_name",
            lease->server_name);
#endif

    for (i = 0; i < 256; i++) {
        u_int8_t *dp = NULL;

        if (ip->client->config->defaults[i].len) {
            if (lease->options[i].len) {
                switch (
                    ip->client->config->default_actions[i]) {
                case ACTION_DEFAULT:
                    dp = lease->options[i].data;
                    len = lease->options[i].len;
                    break;
                case ACTION_SUPERSEDE:
supersede:
                    dp = ip->client->
                        config->defaults[i].data;
                    len = ip->client->
                        config->defaults[i].len;
                    break;
                case ACTION_PREPEND:
                    len = ip->client->
                        config->defaults[i].len +
                        lease->options[i].len;
                    if (len >= sizeof(dbuf)) {
                        warning("no space to %s %s",
                            "prepend option",
                            dhcp_options[i].name);
                        goto supersede;
                    }
                    dp = dbuf;
                    memcpy(dp,
                        ip->client->
                        config->defaults[i].data,
                        ip->client->
                        config->defaults[i].len);
                    memcpy(dp + ip->client->
                        config->defaults[i].len,
                        lease->options[i].data,
                        lease->options[i].len);
                    dp[len] = '\0';
                    break;
                case ACTION_APPEND:
                    len = ip->client->
                        config->defaults[i].len +
                        lease->options[i].len + 1;
                    if (len > sizeof(dbuf)) {
                        warning("no space to %s %s",
                            "append option",
                            dhcp_options[i].name);
                        goto supersede;
                    }
                    dp = dbuf;
                    memcpy(dp,
                        lease->options[i].data,
                        lease->options[i].len);
                    memcpy(dp + lease->options[i].len,
                        ip->client->
                        config->defaults[i].data,
                        ip->client->
                        config->defaults[i].len);
                    dp[len-1] = '\0';
                }
            } else {
                dp = ip->client->
                    config->defaults[i].data;
                len = ip->client->
                    config->defaults[i].len;
            }
        } else if (lease->options[i].len) {
            len = lease->options[i].len;
            dp = lease->options[i].data;
        } else {
            len = 0;
        }
#if 0
        if (len) {
            char name[256];

            if (dhcp_option_ev_name(name, sizeof(name),
                &dhcp_options[i]))
                script_set_env(ip->client, prefix, name,
                    pretty_print_option(i, dp, len, 0, 0));
        }
#endif
    }
#if 0
    snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
    script_set_env(ip->client, prefix, "expiry", tbuf);
#endif
}

int
dhcp_option_ev_name(char *buf, size_t buflen, struct dhcp_option *option)
{
    int i;

    for (i = 0; option->name[i]; i++) {
        if (i + 1 == buflen)
            return 0;
        if (option->name[i] == '-')
            buf[i] = '_';
        else
            buf[i] = option->name[i];
    }

    buf[i] = 0;
    return 1;
}

#if 0
void
go_daemon(void)
{
    static int state = 0;

    if (no_daemon || state)
        return;

    state = 1;

    /* Stop logging to stderr... */
    log_perror = 0;

    if (daemon(1, 0) == -1)
        error("daemon");

    /* we are chrooted, daemon(3) fails to open /dev/null */
    if (nullfd != -1) {
        dup2(nullfd, STDIN_FILENO);
        dup2(nullfd, STDOUT_FILENO);
        dup2(nullfd, STDERR_FILENO);
        close(nullfd);
        nullfd = -1;
    }
}
#endif

int
check_option(struct client_lease *l, int option)
{
    char *opbuf;
    char *sbuf;

    /* we use this, since this is what gets passed to dhclient-script */

    opbuf = pretty_print_option(option, l->options[option].data,
        l->options[option].len, 0, 0);

    sbuf = option_as_string(option, l->options[option].data,
        l->options[option].len);

    switch (option) {
    case DHO_SUBNET_MASK:
    case DHO_TIME_SERVERS:
    case DHO_NAME_SERVERS:
    case DHO_ROUTERS:
    case DHO_DOMAIN_NAME_SERVERS:
    case DHO_LOG_SERVERS:
    case DHO_COOKIE_SERVERS:
    case DHO_LPR_SERVERS:
    case DHO_IMPRESS_SERVERS:
    case DHO_RESOURCE_LOCATION_SERVERS:
    case DHO_SWAP_SERVER:
    case DHO_BROADCAST_ADDRESS:
    case DHO_NIS_SERVERS:
    case DHO_NTP_SERVERS:
    case DHO_NETBIOS_NAME_SERVERS:
    case DHO_NETBIOS_DD_SERVER:
    case DHO_FONT_SERVERS:
    case DHO_DHCP_SERVER_IDENTIFIER:
        if (!ipv4addrs(opbuf)) {
                        warning("Invalid IP address in option(%d): %s", option, opbuf);
            return (0);
        }
        return (1)  ;
    case DHO_HOST_NAME:
    case DHO_DOMAIN_NAME:
    case DHO_NIS_DOMAIN:
        if (!res_hnok(sbuf))
            warning("Bogus Host Name option %d: %s (%s)", option,
                sbuf, opbuf);
        return (1);
    case DHO_PAD:
    case DHO_TIME_OFFSET:
    case DHO_BOOT_SIZE:
    case DHO_MERIT_DUMP:
    case DHO_ROOT_PATH:
    case DHO_EXTENSIONS_PATH:
    case DHO_IP_FORWARDING:
    case DHO_NON_LOCAL_SOURCE_ROUTING:
    case DHO_POLICY_FILTER:
    case DHO_MAX_DGRAM_REASSEMBLY:
    case DHO_DEFAULT_IP_TTL:
    case DHO_PATH_MTU_AGING_TIMEOUT:
    case DHO_PATH_MTU_PLATEAU_TABLE:
    case DHO_INTERFACE_MTU:
    case DHO_ALL_SUBNETS_LOCAL:
    case DHO_PERFORM_MASK_DISCOVERY:
    case DHO_MASK_SUPPLIER:
    case DHO_ROUTER_DISCOVERY:
    case DHO_ROUTER_SOLICITATION_ADDRESS:
    case DHO_STATIC_ROUTES:
    case DHO_TRAILER_ENCAPSULATION:
    case DHO_ARP_CACHE_TIMEOUT:
    case DHO_IEEE802_3_ENCAPSULATION:
    case DHO_DEFAULT_TCP_TTL:
    case DHO_TCP_KEEPALIVE_INTERVAL:
    case DHO_TCP_KEEPALIVE_GARBAGE:
    case DHO_VENDOR_ENCAPSULATED_OPTIONS:
    case DHO_NETBIOS_NODE_TYPE:
    case DHO_NETBIOS_SCOPE:
    case DHO_X_DISPLAY_MANAGER:
    case DHO_DHCP_REQUESTED_ADDRESS:
    case DHO_DHCP_LEASE_TIME:
    case DHO_DHCP_OPTION_OVERLOAD:
    case DHO_DHCP_MESSAGE_TYPE:
    case DHO_DHCP_PARAMETER_REQUEST_LIST:
    case DHO_DHCP_MESSAGE:
    case DHO_DHCP_MAX_MESSAGE_SIZE:
    case DHO_DHCP_RENEWAL_TIME:
    case DHO_DHCP_REBINDING_TIME:
    case DHO_DHCP_CLASS_IDENTIFIER:
    case DHO_DHCP_CLIENT_IDENTIFIER:
    case DHO_DHCP_USER_CLASS_ID:
    case DHO_END:
        return (1);
    default:
        warning("unknown dhcp option value 0x%x", option);
        return (unknown_ok);
    }
}

int
res_hnok(const char *dn)
{
    int pch = PERIOD, ch = *dn++;

    while (ch != '\0') {
        int nch = *dn++;

        if (periodchar(ch)) {
            ;
        } else if (periodchar(pch)) {
            if (!borderchar(ch))
                return (0);
        } else if (periodchar(nch) || nch == '\0') {
            if (!borderchar(ch))
                return (0);
        } else {
            if (!middlechar(ch))
                return (0);
        }
        pch = ch, ch = nch;
    }
    return (1);
}

/* Does buf consist only of dotted decimal ipv4 addrs?
 * return how many if so,
 * otherwise, return 0
 */
int
ipv4addrs(char * buf)
{
    char *tmp;
    struct in_addr jnk;
    int i = 0;

    note("Input: %s", buf);

    do {
        tmp = strtok(buf, " ");
        note("got %s", tmp);
        if( tmp && inet_aton(tmp, &jnk) ) i++;
        buf = NULL;
    } while( tmp );

    return (i);
}


char *
option_as_string(unsigned int code, unsigned char *data, int len)
{
    static char optbuf[32768]; /* XXX */
    char *op = optbuf;
    int opleft = sizeof(optbuf);
    unsigned char *dp = data;

    if (code > 255)
        error("option_as_string: bad code %d", code);

    for (; dp < data + len; dp++) {
        if (!isascii(*dp) || !isprint(*dp)) {
            if (dp + 1 != data + len || *dp != 0) {
                _snprintf(op, opleft, "\\%03o", *dp);
                op += 4;
                opleft -= 4;
            }
        } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
            *dp == '`' || *dp == '\\') {
            *op++ = '\\';
            *op++ = *dp;
            opleft -= 2;
        } else {
            *op++ = *dp;
            opleft--;
        }
    }
    if (opleft < 1)
        goto toobig;
    *op = 0;
    return optbuf;
toobig:
    warning("dhcp option too large");
    return "<error>";
}