dmake: do not set MAKEFLAGS=k

[unleashed/tickless.git] / usr / src / stand / lib / inet / dhcpv4.c

/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Standalone dhcp client.
 */

#pragma ident   "%Z%%M% %I%     %E% SMI"

#include <sys/types.h>
#include <sys/salib.h>
#include <sys/bootconf.h>
#include <sys/bootcmn.h>
#include <sys/socket.h>
#include <sys/isa_defs.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/inetutil.h>
#include <netinet/dhcp.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <dhcp_impl.h>
#include <net/if_types.h>
#include <sys/promif.h>
#include <sys/platnames.h>
#include <socket_inet.h>

#include "ipv4.h"
#include "mac.h"
#include <sys/bootdebug.h>
#include "dhcpv4.h"

static char             *s_n = "INIT";
static enum DHCPSTATE   dhcp_state = INIT;

static PKT              *dhcp_snd_bufp, *dhcp_rcv_bufp;
static int              dhcp_buf_size;

static const uint8_t    magic[] = BOOTMAGIC;    /* RFC1048 */
static uint8_t          opt_discover[]  = { CD_DHCP_TYPE, 1, DISCOVER };
static uint8_t          opt_request[]   = { CD_DHCP_TYPE, 1, REQUEST };
static uint8_t          opt_decline[]   = { CD_DHCP_TYPE, 1, DECLINE };

static uint8_t          dhcp_classid[DHCP_MAX_OPT_SIZE + 3];
static uint8_t          dhcp_clientid[DHCP_MAX_CID_LEN];
static uint8_t          dhcp_clientid_len = 0;

static uint32_t         dhcp_start_time;        /* start time (msecs */
static time_t           dhcp_secs;
static uint32_t         timeout;        /* timeout in milliseconds */

static int              pkt_counter;
PKT_LIST                *list_tl, *list_hd;
PKT_LIST                *state_pl = NULL;

#define PROM_BOOT_CACHED        "bootp-response"
extern char     *bootp_response;        /* bootprop.c */
extern int      pagesize;

/*
 * Do whatever reset actions/initialization actions are generic for every
 * DHCP/bootp message. Set the message type.
 *
 * Returns: the updated options ptr.
 */
static uint8_t *
init_msg(PKT *pkt, uint8_t *pkttype)
{
        static uint32_t xid;

        bzero(pkt, dhcp_buf_size);
        bcopy(magic, pkt->cookie, sizeof (pkt->cookie));
        pkt->op = BOOTREQUEST;
        if (xid == 0)
                bcopy(mac_get_addr_buf()+2, &xid, 4);
        else
                xid++;
        pkt->xid = xid;
        bcopy(pkttype, pkt->options, 3);
        return ((uint8_t *)(pkt->options + 3));
}

/*
 *  Parameter request list.
 */
static void
parameter_request_list(uint8_t **opt)
{
        /*
         * This parameter request list is used in the normal 4-packet
         * DHCPDISCOVER/OFFER/REQUEST/ACK exchange; it must not contain
         * CD_REQUESTED_IP_ADDR or CD_LEASE_TIME.
         */
        static uint8_t  prlist[] = {
            CD_REQUEST_LIST,    /* parameter request list option number */
            4,                  /* number of options requested */
            CD_SUBNETMASK,
            CD_ROUTER,
            CD_HOSTNAME,
            CD_VENDOR_SPEC
            };
        if (opt && *opt) {
                bcopy(prlist, *opt, sizeof (prlist));
                *opt += sizeof (prlist);
        }
}

/*
 * Set hardware specific fields
 */
static void
set_hw_spec_data(PKT *p, uint8_t **opt, uint8_t *pkttype)
{
        char mfg[DHCP_MAX_OPT_SIZE + 1], cbuf[DHCP_MAX_OPT_SIZE + 1];
        uint8_t *tp, *dp;
        int adjust_len, len, i;

        p->htype = mac_arp_type(mac_get_type());
        len = (uchar_t)mac_get_addr_len();
        if (len <= sizeof (p->chaddr)) {
                p->hlen = len;
                bcopy(mac_get_addr_buf(), p->chaddr, len);
        } else {
                uint8_t type = *(pkttype + 2);
                /*
                 * The mac address does not fit in the chaddr
                 * field, thus it can not be sent to the server,
                 * thus server can not unicast the reply. Per
                 * RFC 2131 4.4.1, client can set this bit in
                 * DISCOVER/REQUEST.
                 */
                if ((type == DISCOVER) || (type == REQUEST))
                        p->flags = htons(BCAST_MASK);
        }

        if (opt && *opt) {
                if (dhcp_classid[0] == '\0') {
                        /*
                         * Classids based on mfg name: Commas (,) are
                         * converted to periods (.), and spaces ( ) are removed.
                         */
                        dhcp_classid[0] = CD_CLASS_ID;

                        (void) strncpy(mfg, get_mfg_name(), sizeof (mfg));
                        if (strncmp(mfg, "SUNW", strlen("SUNW")) != 0) {
                                len = strlen("SUNW.");
                                (void) strcpy(cbuf, "SUNW.");
                        } else {
                                len = 0;
                                cbuf[0] = '\0';
                        }
                        len += strlen(mfg);

                        if ((len + 2) < DHCP_MAX_OPT_SIZE) {
                                tp = (uint8_t *)strcat(cbuf, mfg);
                                dp = &dhcp_classid[2];
                                adjust_len = 0;
                                for (i = 0; i < len; i++, tp++) {
                                        if (*tp == ',') {
                                                *dp++ = '.';
                                        } else if (*tp == ' ') {
                                                adjust_len++;
                                        } else {
                                                *dp++ = *tp;
                                        }
                                }
                                len -= adjust_len;
                                dhcp_classid[1] = (uint8_t)len;
                        } else
                                prom_panic("Not enough space for class id");
#ifdef  DHCP_DEBUG
                        printf("%s: Classid: %s\n", s_n, &dhcp_classid[2]);
#endif  /* DHCP_DEBUG */
                }
                bcopy(dhcp_classid, *opt, dhcp_classid[1] + 2);
                *opt += dhcp_classid[1] + 2;
        }
}

static void
flush_list(void)
{
        PKT_LIST *wk, *tmp;

        wk = list_hd;
        while (wk != NULL) {
                tmp = wk;
                wk = wk->next;
                bkmem_free((char *)tmp->pkt, tmp->len);
                bkmem_free((char *)tmp, sizeof (PKT_LIST));
        }
        list_hd = list_tl = NULL;
        pkt_counter = 0;
}

static void
remove_list(PKT_LIST *pl, int flag)
{
        if (list_hd == NULL)
                return;

        if (list_hd == list_tl) {
                list_hd = list_tl = NULL;
        } else if (list_hd == pl) {
                list_hd = pl->next;
                list_hd->prev = NULL;
        } else if (list_tl == pl) {
                list_tl = list_tl->prev;
                list_tl->next = NULL;
        } else {
                pl->prev->next = pl->next;
                pl->next->prev = pl->prev;
        }
        pkt_counter--;
        if (flag) {
                bkmem_free((char *)pl->pkt, pl->len);
                bkmem_free((char *)pl, sizeof (PKT_LIST));
        }
}

/*
 * Collects BOOTP responses. Length has to be right, it has to be
 * a BOOTP reply pkt, with the same XID and HW address as ours. Adds
 * them to the pkt list.
 *
 * Returns 0 if no error processing packet, 1 if an error occurred and/or
 * collection of replies should stop. Used in inet() calls.
 */
static int
bootp_collect(int len)
{
        PKT             *s = (PKT *)dhcp_snd_bufp;
        PKT             *r = (PKT *)dhcp_rcv_bufp;
        PKT_LIST        *pl;

        if (len < sizeof (PKT)) {
                dprintf("%s: BOOTP reply too small: %d\n", s_n, len);
                return (1);
        }
        if (r->op == BOOTREPLY && r->xid == s->xid &&
            bcmp((caddr_t)s->chaddr, (caddr_t)r->chaddr, s->hlen) == 0) {
                /* Add a packet to the pkt list */
                if (pkt_counter > (MAX_PKT_LIST - 1))
                        return (1);     /* got enough packets already */
                if (((pl = (PKT_LIST *)bkmem_zalloc(sizeof (PKT_LIST))) ==
                    NULL) || ((pl->pkt = (PKT *)bkmem_zalloc(len)) == NULL)) {
                        errno = ENOMEM;
                        if (pl != NULL)
                                bkmem_free((char *)pl, sizeof (PKT_LIST));
                        return (1);
                }
                bcopy(dhcp_rcv_bufp, pl->pkt, len);
                pl->len = len;
                if (list_hd == NULL) {
                        list_hd = list_tl = pl;
                        pl->prev = NULL;
                } else {
                        list_tl->next = pl;
                        pl->prev = list_tl;
                        list_tl = pl;
                }
                pkt_counter++;
                pl->next = NULL;
        }
        return (0);
}

/*
 * Checks if BOOTP exchange(s) were successful. Returns 1 if they
 * were, 0 otherwise. Used in inet() calls.
 */
static int
bootp_success(void)
{
        PKT     *s = (PKT *)dhcp_snd_bufp;

        if (list_hd != NULL) {
                /* remember the secs - we may need them later */
                dhcp_secs = ntohs(s->secs);
                return (1);
        }
        s->secs = htons((uint16_t)((prom_gettime() - dhcp_start_time)/1000));
        return (0);
}

/*
 * This function accesses the network. Opens a connection, and binds to
 * it if a client binding doesn't already exist. If 'tries' is 0, then
 * no reply is expected/returned. If 'tries' is non-zero, then 'tries'
 * attempts are made to get a valid response. If 'tol' is not zero,
 * then this function will wait for 'tol' milliseconds for more than one
 * response to a transmit.
 *
 * Returns 0 for success, errno otherwise.
 */
static int
inet(uint32_t size, struct in_addr *src, struct in_addr *dest, uint32_t tries,
    uint32_t tol)
{
        int                     done = B_FALSE, flags, len;
        uint32_t                attempts = 0;
        int                     sd;
        uint32_t                wait_time;      /* Max time collect replies */
        uint32_t                init_timeout;   /* Max time wait ANY reply */
        uint32_t                now;
        struct sockaddr_in      saddr, daddr;

        if ((sd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
                dprintf("%s: Can't open a socket.\n", s_n);
                return (errno);
        }

        flags = 0;

        bzero(&saddr, sizeof (struct sockaddr_in));
        saddr.sin_family = AF_INET;
        saddr.sin_port = htons(IPPORT_BOOTPC);
        saddr.sin_addr.s_addr = htonl(src->s_addr);

        if (bind(sd, (struct sockaddr *)&saddr, sizeof (saddr)) < 0) {
                dprintf("%s: Cannot bind to port %d, errno: %d\n",
                    s_n, IPPORT_BOOTPC, errno);
                (void) socket_close(sd);
                return (errno);
        }

        if (ntohl(dest->s_addr) == INADDR_BROADCAST) {
                int dontroute = B_TRUE;
                (void) setsockopt(sd, SOL_SOCKET, SO_DONTROUTE,
                    (const void *)&dontroute, sizeof (dontroute));
        }

        bzero(&daddr, sizeof (struct sockaddr_in));
        daddr.sin_family = AF_INET;
        daddr.sin_port = htons(IPPORT_BOOTPS);
        daddr.sin_addr.s_addr = htonl(dest->s_addr);
        wait_time = prom_gettime() + tol;

        do {
                if (sendto(sd, (char *)dhcp_snd_bufp, size, flags,
                    (struct sockaddr *)&daddr, sizeof (daddr)) < 0) {
                        dprintf("%s: sendto failed with errno: %d\n",
                            s_n, errno);
                        (void) socket_close(sd);
                        return (errno);
                }
                if (!tries)
                        break;   /* don't bother to check for reply */

                now = prom_gettime();
                if (timeout == 0)
                        timeout = 4000;
                else {
                        timeout <<= 1;
                        if (timeout > 64000)
                                timeout = 64000;
                }
                init_timeout = now + timeout;
                wait_time = now + tol;
                do {
                        if ((len = recvfrom(sd, (char *)dhcp_rcv_bufp,
                            (int)dhcp_buf_size, MSG_DONTWAIT, NULL,
                            NULL)) < 0) {
                                if (errno == EWOULDBLOCK)
                                        continue;       /* DONT WAIT */
                                (void) socket_close(sd);
                                flush_list();
                                return (errno);
                        }

                        if (bootp_collect(len))
                                break;  /* Stop collecting */

                        if (tol != 0) {
                                if (wait_time < prom_gettime())
                                        break; /* collection timeout */
                        }
                } while (prom_gettime() < init_timeout);

                if (bootp_success()) {
                        done = B_TRUE;
                        break;  /* got the goods */
                }
        } while (++attempts < tries);

        (void) socket_close(sd);

        return (done ? 0 : DHCP_NO_DATA);
}

/*
 * Print the message from the server.
 */
static void
prt_server_msg(DHCP_OPT *p)
{
        int len = p->len;
        char scratch[DHCP_MAX_OPT_SIZE + 1];

        if (len > DHCP_MAX_OPT_SIZE)
                len = DHCP_MAX_OPT_SIZE;
        bcopy(p->value, scratch, len);
        scratch[len] = '\0';
        printf("%s: Message from server: '%s'\n", s_n, scratch);
}

/*
 * This function scans the list of OFFERS, and returns the "best" offer.
 * The criteria used for determining this is:
 *
 * The best:
 * DHCP OFFER (not BOOTP), same client_id as ours, same class_id,
 * Longest lease, all the options we need.
 *
 * Not quite as good:
 * DHCP OFFER, no class_id, short lease, only some of the options we need.
 *
 * We're really reach'in
 * BOOTP reply.
 *
 * DON'T select an offer from a server that gave us a configuration we
 * couldn't use. Take this server off the "bad" list when this is done.
 * Next time, we could potentially retry this server's configuration.
 *
 * NOTE: perhaps this bad server should have a counter associated with it.
 */
static PKT_LIST *
select_best(void)
{
        PKT_LIST        *wk, *tk, *best;
        int             err = 0;

        /* Pass one. Scan for options, set appropriate opt field. */
        wk = list_hd;
        while (wk != NULL) {
                if ((err = dhcp_options_scan(wk, B_TRUE)) != 0) {
                        /* Garbled Options. Nuke this pkt. */
                        if (boothowto & RB_DEBUG) {
                                switch (err) {
                                case DHCP_WRONG_MSG_TYPE:
                                        printf("%s: Unexpected DHCP message.\n",
                                            s_n);
                                        break;
                                case DHCP_GARBLED_MSG_TYPE:
                                        printf(
                                            "%s: Garbled DHCP message type.\n",
                                            s_n);
                                        break;
                                case DHCP_BAD_OPT_OVLD:
                                        printf("%s: Bad option overload.\n",
                                            s_n);
                                        break;
                                }
                        }
                        tk = wk;
                        wk = wk->next;
                        remove_list(tk, B_TRUE);
                        continue;
                }
                wk = wk->next;
        }

        /*
         * Pass two. Pick out the best offer. Point system.
         * What's important?
         *      0) DHCP
         *      1) No option overload
         *      2) Encapsulated vendor option
         *      3) Non-null sname and siaddr fields
         *      4) Non-null file field
         *      5) Hostname
         *      6) Subnetmask
         *      7) Router
         */
        best = NULL;
        for (wk = list_hd; wk != NULL; wk = wk->next) {
                wk->offset = 0;
                if (wk->opts[CD_DHCP_TYPE] &&
                    wk->opts[CD_DHCP_TYPE]->len == 1) {
                        if (*wk->opts[CD_DHCP_TYPE]->value != OFFER) {
                                dprintf("%s: Unexpected DHCP message."
                                    " Expected OFFER message.\n", s_n);
                                continue;
                        }
                        if (!wk->opts[CD_LEASE_TIME]) {
                                dprintf("%s: DHCP OFFER message without lease "
                                    "time parameter.\n", s_n);
                                continue;
                        } else {
                                if (wk->opts[CD_LEASE_TIME]->len != 4) {
                                        dprintf("%s: Lease expiration time is "
                                            "garbled.\n", s_n);
                                        continue;
                                }
                        }
                        if (!wk->opts[CD_SERVER_ID]) {
                                dprintf("%s: DHCP OFFER message without server "
                                    "id parameter.\n", s_n);
                                continue;
                        } else {
                                if (wk->opts[CD_SERVER_ID]->len != 4) {
                                        dprintf("%s: Server identifier "
                                            "parameter is garbled.\n", s_n);
                                        continue;
                                }
                        }
                        /* Valid DHCP OFFER. See if we got our parameters. */
                        dprintf("%s: Found valid DHCP OFFER message.\n", s_n);

                        wk->offset += 30;

                        /*
                         * Also could be faked, though more difficult
                         * because the encapsulation is hard to encode
                         * on a BOOTP server; plus there's not as much
                         * real estate in the packet for options, so
                         * it's likely this option would get dropped.
                         */
                        if (wk->opts[CD_VENDOR_SPEC])
                                wk->offset += 80;
                } else
                        dprintf("%s: Found valid BOOTP reply.\n", s_n);

                /*
                 * RFC1048 BOOTP?
                 */
                if (bcmp((caddr_t)wk->pkt->cookie, (caddr_t)magic,
                    sizeof (magic)) == 0) {
                        wk->offset += 5;
                        if (wk->opts[CD_SUBNETMASK])
                                wk->offset++;
                        if (wk->opts[CD_ROUTER])
                                wk->offset++;
                        if (wk->opts[CD_HOSTNAME])
                                wk->offset += 5;

                        /*
                         * Prefer options that have diskless boot significance
                         */
                        if (ntohl(wk->pkt->siaddr.s_addr) != INADDR_ANY)
                                wk->offset += 10; /* server ip */
                        if (wk->opts[CD_OPTION_OVERLOAD] == NULL) {
                                if (wk->pkt->sname[0] != '\0')
                                        wk->offset += 10; /* server name */
                                if (wk->pkt->file[0] != '\0')
                                        wk->offset += 5; /* File to load */
                        }
                }
#ifdef  DHCP_DEBUG
                printf("%s: This server configuration has '%d' points.\n", s_n,
                    wk->offset);
#endif  /* DHCP_DEBUG */
                if (!best)
                        best = wk;
                else {
                        if (best->offset < wk->offset)
                                best = wk;
                }
        }
        if (best) {
#ifdef  DHCP_DEBUG
                printf("%s: Found best: points: %d\n", s_n, best->offset);
#endif  /* DHCP_DEBUG */
                remove_list(best, B_FALSE);
        } else {
                dprintf("%s: No valid BOOTP reply or DHCP OFFER was found.\n",
                    s_n);
        }
        flush_list();   /* toss the remaining list */
        return (best);
}

/*
 * Send a decline message to the generator of the DHCPACK.
 */
static void
dhcp_decline(char *msg, PKT_LIST *pl)
{
        PKT             *pkt;
        uint8_t         *opt, ulen;
        int             pkt_size;
        struct in_addr  nets, ours, t_server, t_yiaddr;

        if (pl != NULL) {
                if (pl->opts[CD_SERVER_ID] != NULL &&
                    pl->opts[CD_SERVER_ID]->len == sizeof (struct in_addr)) {
                        bcopy(pl->opts[CD_SERVER_ID]->value,
                            &t_server, pl->opts[CD_SERVER_ID]->len);
                } else
                        t_server.s_addr = htonl(INADDR_BROADCAST);
                t_yiaddr.s_addr = pl->pkt->yiaddr.s_addr;
        }
        pkt = (PKT *)dhcp_snd_bufp;
        opt = init_msg(pkt, opt_decline);
        set_hw_spec_data(pkt, &opt, opt_decline);

        *opt++ = CD_SERVER_ID;
        *opt++ = sizeof (struct in_addr);
        bcopy(&t_server, opt, sizeof (struct in_addr));
        opt += sizeof (struct in_addr);
        nets.s_addr = htonl(INADDR_BROADCAST);

        /*
         * Use the given yiaddr in our ciaddr field so server can identify us.
         */
        pkt->ciaddr.s_addr = t_yiaddr.s_addr;

        ipv4_getipaddr(&ours);  /* Could be 0, could be yiaddr */
        ours.s_addr = htonl(ours.s_addr);

        ulen = (uint8_t)strlen(msg);
        *opt++ = CD_MESSAGE;
        *opt++ = ulen;
        bcopy(msg, opt, ulen);
        opt += ulen;
        *opt++ = CD_END;

        pkt_size = (uint8_t *)opt - (uint8_t *)pkt;
        if (pkt_size < sizeof (PKT))
                pkt_size = sizeof (PKT);

        timeout = 0;    /* reset timeout */
        (void) inet(pkt_size, &ours, &nets, 0, 0L);
}

/*
 * Implementings SELECTING state of DHCP client state machine.
 */
static int
dhcp_selecting(void)
{
        int             pkt_size;
        PKT             *pkt;
        uint8_t         *opt;
        uint16_t        size;
        uint32_t        lease;
        struct in_addr  nets, ours;

        pkt = (PKT *)dhcp_snd_bufp;
        opt = init_msg(pkt, opt_discover);
        pkt->secs = htons((uint16_t)((prom_gettime() - dhcp_start_time)/1000));

        *opt++ = CD_MAX_DHCP_SIZE;
        *opt++ = sizeof (size);
        size = (uint16_t)(dhcp_buf_size - sizeof (struct ip) -
            sizeof (struct udphdr));
        size = htons(size);
        bcopy(&size, opt, sizeof (size));
        opt += sizeof (size);

        set_hw_spec_data(pkt, &opt, opt_discover);

        *opt++ = CD_LEASE_TIME;
        *opt++ = sizeof (lease);
        lease = htonl(DHCP_PERM);       /* ask for a permanent lease */
        bcopy(&lease, opt, sizeof (lease));
        opt += sizeof (lease);

        /*
         * If a clientid was set using dhcp_set_client_id(), add this
         * to the options.
         */
        if (dhcp_clientid_len > 0) {
                *opt++ = CD_CLIENT_ID;
                *opt++ = dhcp_clientid_len;
                bcopy(dhcp_clientid, opt, dhcp_clientid_len);
                opt += dhcp_clientid_len;
        }

        parameter_request_list(&opt);

        *opt++ = CD_END;

        pkt_size = (uint8_t *)opt - (uint8_t *)pkt;
        if (pkt_size < sizeof (PKT))
                pkt_size = sizeof (PKT);

        nets.s_addr = INADDR_BROADCAST;
        ours.s_addr = INADDR_ANY;
        timeout = 0;    /* reset timeout */

        return (inet(pkt_size, &ours, &nets, DHCP_RETRIES, DHCP_WAIT));
}

/*
 * implements the REQUESTING state of the DHCP client state machine.
 */
static int
dhcp_requesting(void)
{
        PKT_LIST        *pl, *wk;
        PKT             *pkt, *pl_pkt;
        uint8_t         *opt;
        int             pkt_size, err;
        uint32_t        t_time;
        struct in_addr  nets, ours;
        DHCP_OPT        *doptp;
        uint16_t        size;

        /* here we scan the list of OFFERS, select the best one. */
        state_pl = NULL;

        if ((pl = select_best()) == NULL) {
                dprintf("%s: No valid BOOTP reply or DHCP OFFER was found.\n",
                    s_n);
                return (1);
        }

        pl_pkt = pl->pkt;

        /*
         * Check to see if we got an OFFER pkt(s). If not, then We only got
         * a response from a BOOTP server. We'll go to the bound state and
         * try to use that configuration.
         */
        if (pl->opts[CD_DHCP_TYPE] == NULL) {
                if (mac_call_arp(&pl_pkt->yiaddr, NULL, DHCP_ARP_TIMEOUT)) {
                        /* Someone responded! go back to SELECTING state. */
                        printf("%s: Some host already using BOOTP %s.\n", s_n,
                            inet_ntoa(pl_pkt->yiaddr));
                        bkmem_free((char *)pl->pkt, pl->len);
                        bkmem_free((char *)pl, sizeof (PKT_LIST));
                        return (1);
                }
                state_pl = pl;
                return (0);
        }

        /*
         * if we got a message from the server, display it.
         */
        if (pl->opts[CD_MESSAGE])
                prt_server_msg(pl->opts[CD_MESSAGE]);
        /*
         * Assemble a DHCPREQUEST, with the ciaddr field set to 0, since we
         * got here from DISCOVER state. Keep secs field the same for relay
         * agents. We start with the DHCPOFFER packet we got, and the
         * options contained in it to make a requested option list.
         */
        pkt = (PKT *)dhcp_snd_bufp;
        opt = init_msg(pkt, opt_request);

        /* Time from Successful DISCOVER message. */
        pkt->secs = htons((uint16_t)dhcp_secs);

        size = (uint16_t)(dhcp_buf_size - sizeof (struct ip) -
            sizeof (struct udphdr));
        size = htons(size);
        *opt++ = CD_MAX_DHCP_SIZE;
        *opt++ = sizeof (size);
        bcopy(&size, opt, sizeof (size));
        opt += sizeof (size);

        set_hw_spec_data(pkt, &opt, opt_request);
        *opt++ = CD_SERVER_ID;
        *opt++ = pl->opts[CD_SERVER_ID]->len;
        bcopy(pl->opts[CD_SERVER_ID]->value, opt,
            pl->opts[CD_SERVER_ID]->len);
        opt += pl->opts[CD_SERVER_ID]->len;

        /* our offered lease minus boot time */
        *opt++ = CD_LEASE_TIME;
        *opt++ = 4;
        bcopy(pl->opts[CD_LEASE_TIME]->value, &t_time,
            sizeof (t_time));
        t_time = ntohl(t_time);
        if ((uint32_t)t_time != DHCP_PERM)
                t_time -= (uint32_t)dhcp_secs;
        t_time = htonl(t_time);
        bcopy(&t_time, opt, sizeof (t_time));
        opt += sizeof (t_time);

        /* our offered IP address, as required. */
        *opt++ = CD_REQUESTED_IP_ADDR;
        *opt++ = sizeof (struct in_addr);
        bcopy(&pl_pkt->yiaddr, opt, sizeof (struct in_addr));
        opt += sizeof (struct in_addr);

        /*
         * If a clientid was set using dhcp_set_client_id(), add this
         * to the options.
         */
        if (dhcp_clientid_len > 0) {
                *opt++ = CD_CLIENT_ID;
                *opt++ = dhcp_clientid_len;
                bcopy(dhcp_clientid, opt, dhcp_clientid_len);
                opt += dhcp_clientid_len;
        }

        parameter_request_list(&opt);

        *opt++ = CD_END;

        /* Done with the OFFER pkt. */
        bkmem_free((char *)pl->pkt, pl->len);
        bkmem_free((char *)pl, sizeof (PKT_LIST));

        /*
         * We make 4 attempts here. We wait for 2 seconds to accumulate
         * requests, just in case a BOOTP server is too fast!
         */
        pkt_size = (uint8_t *)opt - (uint8_t *)pkt;
        if (pkt_size < sizeof (PKT))
                pkt_size = sizeof (PKT);

        nets.s_addr = INADDR_BROADCAST;
        ours.s_addr = INADDR_ANY;
        timeout = 0;    /* reset timeout */

        if ((err = inet(pkt_size, &ours, &nets, 4, (time_t)2L)) != 0)
                return (err);
        for (wk = list_hd; wk != NULL && state_pl == NULL; wk = wk->next) {
                if (dhcp_options_scan(wk, B_TRUE) != 0 ||
                    !wk->opts[CD_DHCP_TYPE])
                        continue;       /* garbled options */
                switch (*wk->opts[CD_DHCP_TYPE]->value) {
                case ACK:
                        remove_list(wk, B_FALSE);
                        state_pl = wk;
                        break;
                case NAK:
                        printf("%s: rejected by DHCP server: %s\n",
                            s_n, inet_ntoa(*((struct in_addr *)wk->
                            opts[CD_SERVER_ID]->value)));
                        if (wk->opts[CD_MESSAGE])
                                prt_server_msg(wk->opts[CD_MESSAGE]);
                        break;
                default:
                        dprintf("%s: Unexpected DHCP message type.\n", s_n);
                        break;
                }
        }
        flush_list();
        if (state_pl != NULL) {
                if (state_pl->opts[CD_MESSAGE])
                        prt_server_msg(state_pl->opts[CD_MESSAGE]);
                pl_pkt = state_pl->pkt;
                /* arp our new address, just to make sure */
                if (!mac_call_arp(&pl_pkt->yiaddr, NULL, DHCP_ARP_TIMEOUT)) {
                        /*
                         * No response. Check if lease is ok.
                         */
                        doptp = state_pl->opts[CD_LEASE_TIME];
                        if (state_pl->opts[CD_DHCP_TYPE] && (!doptp ||
                            (doptp->len % 4) != 0)) {
                                dhcp_decline("Missing or corrupted lease time",
                                    state_pl);
                                err++;
                        }
                } else {
                        dhcp_decline("IP Address already being used!",
                            state_pl);
                        err++;
                }
                if (err) {
                        bkmem_free((char *)state_pl->pkt, state_pl->len);
                        bkmem_free((char *)state_pl, sizeof (PKT_LIST));
                        state_pl = NULL;
                } else
                        return (0);     /* passes the tests! */
        }
        dprintf("%s: No valid DHCP acknowledge messages received.\n", s_n);
        return (1);
}

/*
 * Implements BOUND state of DHCP client state machine.
 */
static int
dhcp_bound(void)
{
        PKT             *pl_pkt = state_pl->pkt;
        DHCP_OPT        *doptp;
        uint8_t         *tp, *hp;
        int             items, i, fnd, k;
        char            hostname[MAXHOSTNAMELEN+1];
        struct in_addr  subnet, defr, savr, *ipp, xip;

#ifdef  DHCP_DEBUG
        if (dhcp_classid[0] != 0) {
                char    scratch[DHCP_MAX_OPT_SIZE + 1];

                bcopy(&dhcp_classid[2], scratch, dhcp_classid[1]);
                scratch[dhcp_classid[1]] = '\0';
                printf("Your machine is of the class: '%s'.\n", scratch);
        }
#endif  /* DHCP_DEBUG */

        /* First, set the bare essentials. (IP layer parameters) */

        ipv4_getipaddr(&xip);
        if (xip.s_addr != INADDR_ANY)
                ipp = &xip;
        else {
                ipp = &pl_pkt->yiaddr;
                ipp->s_addr = ntohl(ipp->s_addr);
                ipv4_setipaddr(ipp);
        }

        ipp->s_addr = htonl(ipp->s_addr);

        if (boothowto & RB_VERBOSE)
                printf("%s: IP address is: %s\n", s_n, inet_ntoa(*ipp));

        /*
         * Ensure that the Boot NFS READ size, if given, is an int16_t.
         */
        if (state_pl->vs[VS_BOOT_NFS_READSIZE] != NULL) {
                doptp = state_pl->vs[VS_BOOT_NFS_READSIZE];
                if (doptp->len != sizeof (int16_t))
                        state_pl->vs[VS_BOOT_NFS_READSIZE] = NULL;
        }

        /*
         * Set subnetmask. Nice, but not required.
         */
        if (state_pl->opts[CD_SUBNETMASK] != NULL) {
                doptp = state_pl->opts[CD_SUBNETMASK];
                if (doptp->len != 4)
                        state_pl->opts[CD_SUBNETMASK] = NULL;
                else {
                        bcopy(doptp->value, &subnet,
                            sizeof (struct in_addr));
                        dprintf("%s: Setting netmask to: %s\n", s_n,
                            inet_ntoa(subnet));
                        subnet.s_addr = ntohl(subnet.s_addr);
                        ipv4_setnetmask(&subnet);
                }
        }

        /*
         * Set default IP TTL. Nice, but not required.
         */
        if (state_pl->opts[CD_IPTTL] != NULL) {
                doptp = state_pl->opts[CD_IPTTL];
                if (doptp->len > 1)
                        state_pl->opts[CD_IPTTL] = NULL;
                else {
                        doptp = state_pl->opts[CD_IPTTL];
                        ipv4_setmaxttl(*(uint8_t *)doptp->value);
                        dprintf("%s: Setting IP TTL to: %d\n", s_n,
                            *(uint8_t *)doptp->value);
                }
        }

        /*
         * Set default router. Not required, although we'll know soon
         * enough...
         */
        if (state_pl->opts[CD_ROUTER] != NULL) {
                doptp = state_pl->opts[CD_ROUTER];
                if ((doptp->len % 4) != 0) {
                        state_pl->opts[CD_ROUTER] = NULL;
                } else {
                        if ((hp = (uint8_t *)bkmem_alloc(
                            mac_get_hdr_len())) == NULL) {
                                errno = ENOMEM;
                                return (-1);
                        }
                        items = doptp->len / sizeof (struct in_addr);
                        tp = doptp->value;
                        bcopy(tp, &savr, sizeof (struct in_addr));
                        for (i = 0, fnd = 0; i < items; i++) {
                                bcopy(tp, &defr, sizeof (struct in_addr));
                                for (k = 0, fnd = 0; k < 2 && fnd == 0; k++) {
                                        fnd = mac_get_arp(&defr, hp,
                                            mac_get_hdr_len(),
                                            mac_get_arp_timeout());
                                }
                                if (fnd)
                                        break;
                                dprintf(
                                    "%s: Warning: Router %s is unreachable.\n",
                                    s_n, inet_ntoa(defr));
                                tp += sizeof (struct in_addr);
                        }
                        bkmem_free((char *)hp, mac_get_hdr_len());

                        /*
                         * If fnd is 0, we didn't find a working router. We'll
                         * still try to use first default router. If we got
                         * a bad router address (like not on the same net),
                         * we're hosed anyway.
                         */
                        if (!fnd) {
                                dprintf(
                                    "%s: Warning: Using default router: %s\n",
                                    s_n, inet_ntoa(savr));
                                defr.s_addr = savr.s_addr;
                        }
                        /* ipv4_route expects network order IP addresses */
                        (void) ipv4_route(IPV4_ADD_ROUTE, RT_DEFAULT, NULL,
                            &defr);
                }
        }

        /*
         * Set hostname. Not required.
         */
        if (state_pl->opts[CD_HOSTNAME] != NULL) {
                doptp = state_pl->opts[CD_HOSTNAME];
                i = doptp->len;
                if (i > MAXHOSTNAMELEN)
                        i = MAXHOSTNAMELEN;
                bcopy(doptp->value, hostname, i);
                hostname[i] = '\0';
                (void) sethostname(hostname, i);
                if (boothowto & RB_VERBOSE)
                        printf("%s: Hostname is %s\n", s_n, hostname);
        }

        /*
         * We don't care about the lease time.... We can't enforce it anyway.
         */
        return (0);
}

/*
 * Convert the DHCPACK into a pure ASCII boot property for use by the kernel
 * later in the boot process.
 */
static void
create_bootpresponse_bprop(PKT_LIST *pl)
{
        uint_t  buflen;

        if (pl == NULL || bootp_response != NULL)
                return;

        buflen = (pl->len * 2) + 1;     /* extra space for null (1) */
        if ((bootp_response = bkmem_alloc(buflen)) == NULL)
                return;

        if (octet_to_hexascii((uint8_t *)pl->pkt, pl->len, bootp_response,
            &buflen) != 0) {
                bkmem_free(bootp_response, (pl->len * 2) + 1);
                bootp_response = NULL;
        }

}

/*
 * Examines /chosen node for "bootp-response" property. If it exists, this
 * property is the DHCPACK cached there by the PROM's DHCP implementation.
 *
 * If cache_present is B_TRUE, we simply return B_TRUE if the property exists
 * w/o decoding it. If cache_present is B_FALSE, we decode the packet and
 * use it as our state packet for the jump to BOUND mode. Note that it's good
 * enough that the cache exists w/o validation for determining if that's what
 * the user intended.
 *
 * We'll short-circuit the DHCP exchange by accepting this packet. We build a
 * PKT_LIST structure, and copy the bootp-response property value into a
 * PKT buffer we allocated. We then scan the PKT for options, and then
 * set state_pl to point to it.
 *
 * Returns B_TRUE if a packet was cached (and was processed correctly), false
 * otherwise. The caller needs to make the state change from SELECTING to
 * BOUND upon a B_TRUE return from this function.
 */
int
prom_cached_reply(int cache_present)
{
        PKT_LIST        *pl;
        int     len;
        pnode_t chosen;
        char    *prop = PROM_BOOT_CACHED;

        chosen = prom_finddevice("/chosen");
        if (chosen == OBP_NONODE || chosen == OBP_BADNODE)
                chosen = prom_nextnode((pnode_t)0);     /* root node */

        if ((len = prom_getproplen(chosen, prop)) <= 0)
                return (B_FALSE);

        if (cache_present)
                return (B_TRUE);

        if (((pl = (PKT_LIST *)bkmem_zalloc(sizeof (PKT_LIST))) == NULL) ||
            ((pl->pkt = (PKT *)bkmem_zalloc(len)) == NULL)) {
                errno = ENOMEM;
                if (pl != NULL)
                        bkmem_free((char *)pl, sizeof (PKT_LIST));
                return (B_FALSE);
        }

        (void) prom_getprop(chosen, prop, (caddr_t)pl->pkt);

        pl->len = len;

        if (dhcp_options_scan(pl, B_TRUE) != 0) {
                /* garbled packet */
                bkmem_free((char *)pl->pkt, pl->len);
                bkmem_free((char *)pl, sizeof (PKT_LIST));
                return (B_FALSE);
        }

        state_pl = pl;
        return (B_TRUE);
}

/*
 * Perform DHCP to acquire what we used to get using rarp/bootparams.
 * Returns 0 for success, nonzero otherwise.
 *
 * DHCP client state machine.
 */
int
dhcp(void)
{
        int     err = 0;
        int     done = B_FALSE;

        dhcp_buf_size = mac_get_mtu();
        dhcp_snd_bufp = (PKT *)bkmem_alloc(dhcp_buf_size);
        dhcp_rcv_bufp = (PKT *)bkmem_alloc(dhcp_buf_size);

        if (dhcp_snd_bufp == NULL || dhcp_rcv_bufp == NULL) {
                if (dhcp_snd_bufp != NULL)
                        bkmem_free((char *)dhcp_snd_bufp, dhcp_buf_size);
                if (dhcp_rcv_bufp != NULL)
                        bkmem_free((char *)dhcp_rcv_bufp, dhcp_buf_size);
                errno = ENOMEM;
                return (-1);
        }

        while (err == 0 && !done) {
                switch (dhcp_state) {
                case INIT:

                        s_n = "INIT";
                        if (prom_cached_reply(B_FALSE)) {
                                dprintf("%s: Using PROM cached BOOT reply...\n",
                                    s_n);
                                dhcp_state = BOUND;
                        } else {
                                dhcp_state = SELECTING;
                                dhcp_start_time = prom_gettime();
                        }
                        break;

                case SELECTING:

                        s_n = "SELECTING";
                        err = dhcp_selecting();
                        switch (err) {
                        case 0:
                                dhcp_state = REQUESTING;
                                break;
                        case DHCP_NO_DATA:
                                dprintf(
                                    "%s: No DHCP response after %d tries.\n",
                                    s_n, DHCP_RETRIES);
                                break;
                        default:
                                /* major network problems */
                                dprintf("%s: Network transaction failed: %d\n",
                                    s_n, err);
                                break;
                        }
                        break;

                case REQUESTING:

                        s_n = "REQUESTING";
                        err = dhcp_requesting();
                        switch (err) {
                        case 0:
                                dhcp_state = BOUND;
                                break;
                        case DHCP_NO_DATA:
                                dprintf("%s: Request timed out.\n", s_n);
                                dhcp_state = SELECTING;
                                err = 0;
                                (void) sleep(10);
                                break;
                        default:
                                /* major network problems */
                                dprintf("%s: Network transaction failed: %d\n",
                                    s_n, err);
                                break;
                        }
                        break;

                case BOUND:

                        /*
                         * We just "give up" if bound state fails.
                         */
                        s_n = "BOUND";
                        if ((err = dhcp_bound()) == 0) {
                                dhcp_state = CONFIGURED;
                        }
                        break;

                case CONFIGURED:
                        s_n = "CONFIGURED";
                        create_bootpresponse_bprop(state_pl);
                        done = B_TRUE;
                        break;
                }
        }
        bkmem_free((char *)dhcp_snd_bufp, dhcp_buf_size);
        bkmem_free((char *)dhcp_rcv_bufp, dhcp_buf_size);

        return (err);
}

/*
 * Returns a copy of the DHCP-supplied value of the parameter requested
 * by code.
 */
boolean_t
dhcp_getinfo(uchar_t optcat, uint16_t code, uint16_t optsize, void *value,
    size_t *vallenp)
{
        size_t          len = *vallenp;

        if (dhcp_getinfo_pl(state_pl, optcat, code,
            optsize, value, &len)) {

                if (len <= *vallenp) {
                        *vallenp = len;
                        return (B_TRUE);
                }
        }

        return (B_FALSE);
}

/*
 * Sets the clientid option.
 */
void
dhcp_set_client_id(uint8_t *clientid, uint8_t clientid_len)
{
        bcopy(clientid, dhcp_clientid, clientid_len);
        dhcp_clientid_len = clientid_len;
}