/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

/*
 * rarpd.c  Reverse-ARP server.
 * Refer to RFC 903 "A Reverse Address Resolution Protocol".
 */

#define _REENTRANT

#include        <thread.h>
#include        <synch.h>
#include        <stdlib.h>
#include        <unistd.h>
#include        <sys/resource.h>
#include        <stdio.h>
#include        <stdio_ext.h>
#include        <stdarg.h>
#include        <string.h>
#include        <fcntl.h>
#include        <sys/types.h>
#include        <dirent.h>
#include        <syslog.h>
#include        <netdb.h>
#include        <errno.h>
#include        <sys/socket.h>
#include        <sys/sockio.h>
#include        <net/if.h>
#include        <netinet/if_ether.h>
#include        <netinet/in.h>
#include        <arpa/inet.h>
#include        <stropts.h>
#include        <libinetutil.h>
#include        <libdlpi.h>
#include        <net/if_types.h>
#include        <net/if_dl.h>

#define BOOTDIR         "/tftpboot"     /* boot files directory */
#define DEVIP           "/dev/ip"       /* path to ip driver */
#define DEVARP          "/dev/arp"      /* path to arp driver */

#define BUFSIZE         2048            /* max receive frame length */
#define MAXPATHL        128             /* max path length */
#define MAXHOSTL        128             /* max host name length */
#define MAXIFS          256

/*
 * Logical network devices
 */
struct  ifdev {
        char            ldevice[IFNAMSIZ];
        int             lunit;
        ipaddr_t        ipaddr;                 /* network order */
        ipaddr_t        if_netmask;             /* host order */
        ipaddr_t        if_ipaddr;              /* host order */
        ipaddr_t        if_netnum;              /* host order, with subnet */
        struct ifdev *next;
};

/*
 * Physical network device
 */
struct  rarpdev {
        char            device[DLPI_LINKNAME_MAX];
        uint_t          unit;
        dlpi_handle_t   dh_rarp;
        uchar_t         physaddr[DLPI_PHYSADDR_MAX];
                                                /* mac address of interface */
        uint_t          physaddrlen;            /* mac address length */
        int             ifrarplen;              /* size of rarp data packet */
        struct ifdev    *ifdev;                 /* private interface info */
        struct rarpdev  *next;                  /* list of managed devices */
};

struct  rarpreply {
        struct rarpdev          *rdev;          /* which device reply for */
        struct timeval          tv;             /* send RARP reply by when */
        uchar_t                 *lldest;        /* target mac to send reply */
        uchar_t                 *arprep;        /* [R]ARP response */
        struct rarpreply        *next;
};

static struct rarpreply *delay_list;
static sema_t           delay_sema;
static mutex_t          delay_mutex;
static mutex_t          debug_mutex;

static struct rarpdev   *rarpdev_head;

/*
 * Globals initialized before multi-threading
 */
static char     *cmdname;               /* command name from argv[0] */
static int      dflag = 0;              /* enable diagnostics */
static int      aflag = 0;              /* start rarpd on all interfaces */

static void     getintf(void);
static struct rarpdev *find_device(ifspec_t *);
static void     init_rarpdev(struct rarpdev *);
static void     do_rarp(void *);
static void     rarp_request(struct rarpdev *, struct arphdr *,
                    uchar_t *);
static void     add_arp(struct rarpdev *, uchar_t *, uchar_t *);
static void     arp_request(struct rarpdev *, struct arphdr *, uchar_t *);
static void     do_delay_write(void *);
static void     delay_write(struct rarpdev *, struct rarpreply *);
static int      mightboot(ipaddr_t);
static void     get_ifdata(char *, int, ipaddr_t *, ipaddr_t *);
static int      get_ipaddr(struct rarpdev *, uchar_t *, uchar_t *, ipaddr_t *);
static int      strioctl(int, int, int, int, char *);
static void     usage();
static void     syserr(const char *);
/*PRINTFLIKE1*/
static void     error(const char *, ...);
static void     debug(char *, ...);

extern  int     optind;
extern  char    *optarg;

int
main(int argc, char *argv[])
{
        int             c;
        struct rlimit rl;
        struct rarpdev  *rdev;
        int             i;

        cmdname = argv[0];

        while ((c = getopt(argc, argv, "ad")) != -1) {
                switch (c) {
                case 'a':
                        aflag = 1;
                        break;

                case 'd':
                        dflag = 1;
                        break;

                default:
                        usage();
                }
        }

        if ((!aflag && (argc - optind) != 2) ||
            (aflag && (argc - optind) != 0)) {
                usage();
                /* NOTREACHED */
        }

        if (!dflag) {
                /*
                 * Background
                 */
                switch (fork()) {
                        case -1:        /* error */
                                syserr("fork");
                                /*NOTREACHED*/

                        case 0:         /* child */
                                break;

                        default:        /* parent */
                                return (0);
                }
                for (i = 0; i < 3; i++) {
                        (void) close(i);
                }
                (void) open("/", O_RDONLY, 0);
                (void) dup2(0, 1);
                (void) dup2(0, 2);
                /*
                 * Detach terminal
                 */
                if (setsid() < 0)
                        syserr("setsid");
        }

        rl.rlim_cur = RLIM_INFINITY;
        rl.rlim_max = RLIM_INFINITY;
        if (setrlimit(RLIMIT_NOFILE, &rl) == -1)
                syserr("setrlimit");
        (void) enable_extended_FILE_stdio(-1, -1);

        (void) openlog(cmdname, LOG_PID, LOG_DAEMON);

        if (aflag) {
                /*
                 * Get each interface name and load rarpdev list.
                 */
                getintf();
        } else {
                ifspec_t        ifsp;
                struct ifdev    *ifdev;
                char            buf[IFNAMSIZ + 1];

                /*
                 * Load specified device as only element of the list.
                 */
                rarpdev_head = (struct rarpdev *)calloc(1,
                    sizeof (struct rarpdev));
                if (rarpdev_head == NULL) {
                        error("out of memory");
                }
                (void) strncpy(buf, argv[optind], IFNAMSIZ);
                (void) strncat(buf, argv[optind + 1], IFNAMSIZ - strlen(buf));

                if ((ifdev = calloc(1, sizeof (struct ifdev))) == NULL) {
                        error("out of memory");
                }

                if (!ifparse_ifspec(buf, &ifsp))
                        error("invalid interface specification");

                if (ifsp.ifsp_lunvalid) {
                        (void) snprintf(ifdev->ldevice,
                            sizeof (ifdev->ldevice), "%s%d:",
                            ifsp.ifsp_devnm, ifsp.ifsp_ppa);
                        ifdev->lunit = ifsp.ifsp_lun;
                } else {
                        ifdev->lunit = -1; /* no logical unit */
                }
                (void) strlcpy(rarpdev_head->device, ifsp.ifsp_devnm,
                    sizeof (rarpdev_head->device));
                rarpdev_head->unit = ifsp.ifsp_ppa;

                ifdev->next = rarpdev_head->ifdev;
                rarpdev_head->ifdev = ifdev;
        }

        /*
         * Initialize each rarpdev.
         */
        for (rdev = rarpdev_head; rdev != NULL; rdev = rdev->next) {
                init_rarpdev(rdev);
        }

        (void) sema_init(&delay_sema, 0, USYNC_THREAD, NULL);
        (void) mutex_init(&delay_mutex, USYNC_THREAD, NULL);
        (void) mutex_init(&debug_mutex, USYNC_THREAD, NULL);

        /*
         * Start delayed processing thread.
         */
        (void) thr_create(NULL, 0, (void *(*)(void *))do_delay_write, NULL,
            THR_NEW_LWP, NULL);

        /*
         * Start RARP processing for each device.
         */
        for (rdev = rarpdev_head; rdev != NULL; rdev = rdev->next) {
                if (rdev->dh_rarp != NULL) {
                        (void) thr_create(NULL, 0,
                            (void *(*)(void *))do_rarp, (void *)rdev,
                            THR_NEW_LWP, NULL);
                }
        }

        /*
         * Exit main() thread
         */
        thr_exit(NULL);

        return (0);
}

static void
getintf(void)
{
        int             fd;
        int             numifs;
        unsigned        bufsize;
        struct ifreq    *reqbuf;
        struct ifconf   ifconf;
        struct ifreq    *ifr;
        struct rarpdev  *rdev;
        struct ifdev    *ifdev;

        /*
         * Open the IP provider.
         */
        if ((fd = open(DEVIP, 0)) < 0)
                syserr(DEVIP);

        /*
         * Ask IP for the list of configured interfaces.
         */
        if (ioctl(fd, SIOCGIFNUM, (char *)&numifs) < 0) {
                numifs = MAXIFS;
        }
        bufsize = numifs * sizeof (struct ifreq);
        reqbuf = (struct ifreq *)malloc(bufsize);
        if (reqbuf == NULL) {
                error("out of memory");
        }

        ifconf.ifc_len = bufsize;
        ifconf.ifc_buf = (caddr_t)reqbuf;
        if (ioctl(fd, SIOCGIFCONF, (char *)&ifconf) < 0)
                syserr("SIOCGIFCONF");

        /*
         * Initialize a rarpdev for each interface.
         */
        for (ifr = ifconf.ifc_req; ifconf.ifc_len > 0;
            ifr++, ifconf.ifc_len -= sizeof (struct ifreq)) {
                ifspec_t        ifsp;

                if (ioctl(fd, SIOCGIFFLAGS, (char *)ifr) < 0) {
                        syserr("ioctl SIOCGIFFLAGS");
                        exit(1);
                }
                if ((ifr->ifr_flags & IFF_LOOPBACK) ||
                    !(ifr->ifr_flags & IFF_UP) ||
                    !(ifr->ifr_flags & IFF_BROADCAST) ||
                    (ifr->ifr_flags & IFF_NOARP) ||
                    (ifr->ifr_flags & IFF_POINTOPOINT))
                        continue;

                if (!ifparse_ifspec(ifr->ifr_name, &ifsp))
                        error("ifparse_ifspec failed");

                /*
                 * Look for an existing device for logical interfaces.
                 */
                if ((rdev = find_device(&ifsp)) == NULL) {
                        rdev = calloc(1, sizeof (struct rarpdev));
                        if (rdev == NULL)
                                error("out of memory");

                        (void) strlcpy(rdev->device, ifsp.ifsp_devnm,
                            sizeof (rdev->device));
                        rdev->unit = ifsp.ifsp_ppa;

                        rdev->next = rarpdev_head;
                        rarpdev_head = rdev;
                }

                if ((ifdev = calloc(1, sizeof (struct ifdev))) == NULL)
                        error("out of memory");

                if (ifsp.ifsp_lunvalid) {
                        (void) snprintf(ifdev->ldevice,
                            sizeof (ifdev->ldevice), "%s%d:",
                            ifsp.ifsp_devnm, ifsp.ifsp_ppa);
                        ifdev->lunit = ifsp.ifsp_lun;
                } else
                        ifdev->lunit = -1; /* no logical unit */

                ifdev->next = rdev->ifdev;
                rdev->ifdev = ifdev;
        }
        (void) free((char *)reqbuf);
}

static struct rarpdev *
find_device(ifspec_t *specp)
{
        struct rarpdev  *rdev;

        for (rdev = rarpdev_head; rdev != NULL; rdev = rdev->next) {
                if (specp->ifsp_ppa == rdev->unit &&
                    strcmp(specp->ifsp_devnm, rdev->device) == 0)
                        return (rdev);
        }
        return (NULL);
}

static void
init_rarpdev(struct rarpdev *rdev)
{
        char            *dev;
        int             unit;
        struct ifdev    *ifdev;
        int             retval;
        char            *str = NULL;
        uint_t          physaddrlen = DLPI_PHYSADDR_MAX;
        char            linkname[DLPI_LINKNAME_MAX];
        dlpi_handle_t   dh;

        (void) snprintf(linkname, DLPI_LINKNAME_MAX, "%s%d", rdev->device,
            rdev->unit);
        /*
         * Open datalink provider and get our mac address.
         */
        if ((retval = dlpi_open(linkname, &dh, 0)) != DLPI_SUCCESS) {
                error("cannot open link %s: %s", linkname,
                    dlpi_strerror(retval));
        }

        if ((retval = dlpi_bind(dh, ETHERTYPE_REVARP, NULL)) != DLPI_SUCCESS) {
                dlpi_close(dh);
                error("dlpi_bind failed: %s", dlpi_strerror(retval));
        }

        /*
         * Save our mac address.
         */
        if ((retval = dlpi_get_physaddr(dh, DL_CURR_PHYS_ADDR, rdev->physaddr,
            &physaddrlen)) != DLPI_SUCCESS) {
                dlpi_close(dh);
                error("dlpi_get_physaddr failed: %s", dlpi_strerror(retval));
        }

        rdev->physaddrlen = physaddrlen;
        rdev->ifrarplen = sizeof (struct arphdr) + (2 * sizeof (ipaddr_t)) +
            (2 * physaddrlen);

        if (dflag) {
                str = _link_ntoa(rdev->physaddr, str,
                    rdev->physaddrlen, IFT_OTHER);
                if (str != NULL) {
                        debug("device %s physical address %s", linkname, str);
                        free(str);
                }
        }

        /*
         * Assign dlpi handle to rdev.
         */
        rdev->dh_rarp = dh;

        /*
         * Get the IP address and netmask from directory service for
         * each logical interface.
         */
        for (ifdev = rdev->ifdev; ifdev != NULL; ifdev = ifdev->next) {
                /*
                 * If lunit == -1 then this is the primary interface name.
                 */
                if (ifdev->lunit == -1) {
                        dev = rdev->device;
                        unit = rdev->unit;
                } else {
                        dev = ifdev->ldevice;
                        unit = ifdev->lunit;
                }
                get_ifdata(dev, unit, &ifdev->if_ipaddr, &ifdev->if_netmask);

                /*
                 * Use IP address of the interface.
                 */
                ifdev->if_netnum = ifdev->if_ipaddr & ifdev->if_netmask;
                ifdev->ipaddr = (ipaddr_t)htonl(ifdev->if_ipaddr);
        }
}

static void
do_rarp(void *buf)
{
        struct rarpdev *rdev = buf;
        char    *cause;
        struct arphdr *ans;
        uchar_t *shost;
        uint_t  saddrlen;
        size_t  anslen = rdev->ifrarplen;
        char    *str = NULL;
        int     retval;

        if (((shost = malloc(rdev->physaddrlen)) == NULL) ||
            ((ans = malloc(rdev->ifrarplen)) == NULL))
                syserr("malloc");

        if (dflag) {
                str = _link_ntoa(rdev->physaddr, str, rdev->physaddrlen,
                    IFT_OTHER);
                if (str != NULL) {
                        debug("starting rarp service on device %s%d physical"
                            " address %s", rdev->device, rdev->unit, str);
                        free(str);
                }
        }

        /*
         * Read RARP packets and respond to them.
         */
        for (;;) {
                saddrlen = DLPI_PHYSADDR_MAX;
                retval = dlpi_recv(rdev->dh_rarp, shost,
                    &saddrlen, ans, &anslen, -1, NULL);
                if (retval == DLPI_ETIMEDOUT) {
                        continue;
                } else if (retval != DLPI_SUCCESS) {
                        error("error in dlpi_recv %s: %s", rdev->dh_rarp,
                            dlpi_strerror(retval));
                }

                cause = NULL;

                if (anslen < rdev->ifrarplen)
                        cause = "short packet";
                else if (ans->ar_hrd != htons(ARPHRD_ETHER))
                        cause = "hardware type not Ethernet";
                else if (ans->ar_pro != htons(ETHERTYPE_IP))
                        cause = "protocol type not IP";
                else if (ans->ar_hln != rdev->physaddrlen)
                        cause = "unexpected hardware address length";
                else if (ans->ar_pln != sizeof (ipaddr_t))
                        cause = "unexpected protocol address length";
                if (cause != NULL) {
                        if (dflag)
                                debug("RARP packet received but "
                                    "discarded: %s", cause);
                        continue;
                }

                /*
                 * Handle the request.
                 */
                switch (ntohs(ans->ar_op)) {
                case REVARP_REQUEST:
                        rarp_request(rdev, ans, shost);
                        break;

                case ARPOP_REQUEST:
                        arp_request(rdev, ans, shost);
                        break;

                case REVARP_REPLY:
                        if (dflag)
                                debug("REVARP_REPLY ignored");
                        break;

                case ARPOP_REPLY:
                        if (dflag)
                                debug("ARPOP_REPLY ignored");
                        break;

                default:
                        if (dflag)
                                debug("unknown opcode 0x%x", ans->ar_op);
                        break;
                }
        }
}

/*
 * Reverse address determination and allocation code.
 */
static void
rarp_request(struct rarpdev *rdev, struct arphdr *rp, uchar_t *shost)
{
        ipaddr_t                tpa,  spa;
        struct  rarpreply       *rrp;
        uchar_t                 *shap, *thap, *spap, *tpap;
        char                    *str = NULL;
        int                     retval;

        shap = (uchar_t *)rp + sizeof (struct arphdr);
        spap = shap + rp->ar_hln;
        thap = spap + rp->ar_pln;
        tpap = thap + rp->ar_hln;

        if (dflag) {
                str = _link_ntoa(thap, str, rdev->physaddrlen, IFT_OTHER);
                if (str != NULL) {
                        debug("RARP_REQUEST for %s", str);
                        free(str);
                }
        }

        /*
         * Third party lookups are rare and wonderful.
         */
        if ((memcmp(shap, thap, rdev->physaddrlen) != 0) ||
            (memcmp(shap, shost, rdev->physaddrlen) != 0)) {
                if (dflag)
                        debug("weird (3rd party lookup)");
        }

        /*
         * Fill in given parts of reply packet.
         */
        (void) memcpy(shap, rdev->physaddr, rdev->physaddrlen);

        /*
         * If a good address is stored in our lookup tables, return it
         * immediately or after a delay.  Store it in our kernel's ARP cache.
         */
        if (get_ipaddr(rdev, thap, tpap, &spa))
                return;
        (void) memcpy(spap, &spa, sizeof (spa));

        add_arp(rdev, tpap, thap);

        rp->ar_op = htons(REVARP_REPLY);

        if (dflag) {
                struct in_addr addr;

                (void) memcpy(&addr, tpap, sizeof (ipaddr_t));
                debug("good lookup, maps to %s", inet_ntoa(addr));
        }

        rrp = calloc(1, sizeof (struct rarpreply) + rdev->physaddrlen +
            rdev->ifrarplen);
        if (rrp == NULL)
                error("out of memory");
        rrp->lldest = (uchar_t *)rrp + sizeof (struct rarpreply);
        rrp->arprep = rrp->lldest + rdev->physaddrlen;

        /*
         * Create rarpreply structure.
         */
        (void) gettimeofday(&rrp->tv, NULL);
        rrp->tv.tv_sec += 3;    /* delay */
        rrp->rdev = rdev;
        (void) memcpy(rrp->lldest, shost, rdev->physaddrlen);
        (void) memcpy(rrp->arprep, rp, rdev->ifrarplen);

        /*
         * If this is diskless and we're not its bootserver, let the
         * bootserver reply first by delaying a while.
         */
        (void) memcpy(&tpa, tpap, sizeof (ipaddr_t));
        if (mightboot(ntohl(tpa))) {
                retval = dlpi_send(rdev->dh_rarp, rrp->lldest,
                    rdev->physaddrlen, rrp->arprep, rdev->ifrarplen, NULL);
                if (retval != DLPI_SUCCESS) {
                        error("dlpi_send failed: %s", dlpi_strerror(retval));
                } else if (dflag) {
                        debug("immediate reply sent");
                }
                (void) free(rrp);
        } else {
                delay_write(rdev, rrp);
        }
}

/*
 * Download an ARP entry into our kernel.
 */
static void
add_arp(struct rarpdev *rdev, uchar_t *ip, uchar_t *laddr)
{
        struct xarpreq ar;
        struct sockaddr_in      *sin;
        int     fd;

        /*
         * Common part of query or set.
         */
        (void) memset(&ar, 0, sizeof (ar));
        ar.xarp_pa.ss_family = AF_INET;
        sin = (struct sockaddr_in *)&ar.xarp_pa;
        (void) memcpy(&sin->sin_addr, ip, sizeof (ipaddr_t));

        /*
         * Open the IP provider.
         */
        if ((fd = open(DEVARP, 0)) < 0)
                syserr(DEVARP);

        /*
         * Set the entry.
         */
        (void) memcpy(LLADDR(&ar.xarp_ha), laddr, rdev->physaddrlen);
        ar.xarp_ha.sdl_alen = rdev->physaddrlen;
        ar.xarp_ha.sdl_family = AF_LINK;
        (void) strioctl(fd, SIOCDXARP, -1, sizeof (struct xarpreq),
            (char *)&ar);
        if (strioctl(fd, SIOCSXARP, -1, sizeof (struct xarpreq),
            (char *)&ar) < 0)
                syserr("SIOCSXARP");

        (void) close(fd);
}

/*
 * The RARP spec says we must be able to process ARP requests,
 * even through the packet type is RARP.  Let's hope this feature
 * is not heavily used.
 */
static void
arp_request(struct rarpdev *rdev, struct arphdr *rp, uchar_t *shost)
{
        struct  rarpreply       *rrp;
        struct ifdev            *ifdev;
        uchar_t                 *shap, *thap, *spap, *tpap;
        int                     retval;

        shap = (uchar_t *)rp + sizeof (struct arphdr);
        spap = shap + rp->ar_hln;
        thap = spap + rp->ar_pln;
        tpap = thap + rp->ar_hln;

        if (dflag)
                debug("ARPOP_REQUEST");

        for (ifdev = rdev->ifdev; ifdev != NULL; ifdev = ifdev->next) {
                if (memcmp(&ifdev->ipaddr, tpap, sizeof (ipaddr_t)) == 0)
                        break;
        }
        if (ifdev == NULL)
                return;

        rp->ar_op = ARPOP_REPLY;
        (void) memcpy(shap, rdev->physaddr, rdev->physaddrlen);
        (void) memcpy(spap, &ifdev->ipaddr, sizeof (ipaddr_t));
        (void) memcpy(thap, rdev->physaddr, rdev->physaddrlen);

        add_arp(rdev, tpap, thap);

        /*
         * Create rarp reply structure.
         */
        rrp = calloc(1, sizeof (struct rarpreply) + rdev->physaddrlen +
            rdev->ifrarplen);
        if (rrp == NULL)
                error("out of memory");
        rrp->lldest = (uchar_t *)rrp + sizeof (struct rarpreply);
        rrp->arprep = rrp->lldest + rdev->physaddrlen;
        rrp->rdev = rdev;

        (void) memcpy(rrp->lldest, shost, rdev->physaddrlen);
        (void) memcpy(rrp->arprep, rp, rdev->ifrarplen);

        retval = dlpi_send(rdev->dh_rarp, rrp->lldest, rdev->physaddrlen,
            rrp->arprep, rdev->ifrarplen, NULL);
        free(rrp);
        if (retval != DLPI_SUCCESS)
                error("dlpi_send failed: %s", dlpi_strerror(retval));
}

/* ARGSUSED */
static void
do_delay_write(void *buf)
{
        struct  timeval         tv;
        struct  rarpreply       *rrp;
        struct  rarpdev         *rdev;
        int                     err;

        for (;;) {
                if ((err = sema_wait(&delay_sema)) != 0) {
                        if (err == EINTR)
                                continue;
                        error("do_delay_write: sema_wait failed");
                }

                (void) mutex_lock(&delay_mutex);
                rrp = delay_list;
                rdev = rrp->rdev;
                delay_list = delay_list->next;
                (void) mutex_unlock(&delay_mutex);

                (void) gettimeofday(&tv, NULL);
                if (tv.tv_sec < rrp->tv.tv_sec)
                        (void) sleep(rrp->tv.tv_sec - tv.tv_sec);

                err = dlpi_send(rdev->dh_rarp, rrp->lldest, rdev->physaddrlen,
                    rrp->arprep, rdev->ifrarplen, NULL);
                if (err != DLPI_SUCCESS)
                        error("dlpi_send failed: %s", dlpi_strerror(err));

                (void) free(rrp);
        }
}

/* ARGSUSED */
static void
delay_write(struct rarpdev *rdev, struct rarpreply *rrp)
{
        struct  rarpreply       *trp;

        (void) mutex_lock(&delay_mutex);
        if (delay_list == NULL) {
                delay_list = rrp;
        } else {
                trp = delay_list;
                while (trp->next != NULL)
                        trp = trp->next;
                trp->next = rrp;
        }
        (void) mutex_unlock(&delay_mutex);

        (void) sema_post(&delay_sema);
}

/*
 * See if we have a TFTP boot file for this guy. Filenames in TFTP
 * boot requests are of the form <ipaddr> for Sun-3's and of the form
 * <ipaddr>.<arch> for all other architectures.  Since we don't know
 * the client's architecture, either format will do.
 */
static int
mightboot(ipaddr_t ipa)
{
        char path[MAXPATHL];
        DIR *dirp;
        struct dirent *dp;

        (void) snprintf(path, sizeof (path), "%s/%08X", BOOTDIR, ipa);

        /*
         * Try a quick access() first.
         */
        if (access(path, 0) == 0)
                return (1);

        /*
         * Not there, do it the slow way by
         * reading through the directory.
         */
        (void) sprintf(path, "%08X", ipa);

        if (!(dirp = opendir(BOOTDIR)))
                return (0);

        while ((dp = readdir(dirp)) != NULL) {
                if (strncmp(dp->d_name, path, 8) != 0)
                        continue;
                if ((strlen(dp->d_name) != 8) && (dp->d_name[8] != '.'))
                        continue;
                break;
        }

        (void) closedir(dirp);

        return ((dp != NULL) ? 1 : 0);
}

/*
 * Get our IP address and local netmask.
 */
static void
get_ifdata(char *dev, int unit, ipaddr_t *ipp, ipaddr_t *maskp)
{
        int     fd;
        struct  ifreq   ifr;
        struct  sockaddr_in     *sin;

        /* LINTED pointer */
        sin = (struct sockaddr_in *)&ifr.ifr_addr;

        /*
         * Open the IP provider.
         */
        if ((fd = open(DEVIP, 0)) < 0)
                syserr(DEVIP);

        /*
         * Ask IP for our IP address.
         */
        (void) snprintf(ifr.ifr_name, sizeof (ifr.ifr_name), "%s%d", dev, unit);
        if (strioctl(fd, SIOCGIFADDR, -1, sizeof (struct ifreq),
            (char *)&ifr) < 0)
                syserr("SIOCGIFADDR");
        *ipp = (ipaddr_t)ntohl(sin->sin_addr.s_addr);

        if (dflag)
                debug("device %s%d address %s", dev, unit,
                    inet_ntoa(sin->sin_addr));

        /*
         * Ask IP for our netmask.
         */
        if (strioctl(fd, SIOCGIFNETMASK, -1, sizeof (struct ifreq),
            (char *)&ifr) < 0)
                syserr("SIOCGIFNETMASK");
        *maskp = (ipaddr_t)ntohl(sin->sin_addr.s_addr);

        if (dflag)
                debug("device %s%d subnet mask %s", dev, unit,
                    inet_ntoa(sin->sin_addr));

        /*
         * Thankyou ip.
         */
        (void) close(fd);
}

/*
 * Translate mac address to IP address.
 * Return 0 on success, nonzero on failure.
 */
static int
get_ipaddr(struct rarpdev *rdev, uchar_t *laddr, uchar_t *ipp, ipaddr_t *ipaddr)
{
        char host[MAXHOSTL];
        char hbuffer[BUFSIZE];
        struct hostent *hp, res;
        int herror;
        struct in_addr addr;
        char    **p;
        struct ifdev *ifdev;

        if (rdev->physaddrlen != ETHERADDRL) {
                if (dflag)
                        debug("%s %s", " cannot map non 6 byte hardware ",
                            "address to IP address");
                return (1);
        }

        /*
         * Translate mac address to hostname and IP address.
         */
        if (ether_ntohost(host, (struct ether_addr *)laddr) != 0 ||
            !(hp = gethostbyname_r(host, &res, hbuffer, sizeof (hbuffer),
            &herror)) ||
            hp->h_addrtype != AF_INET || hp->h_length != sizeof (ipaddr_t)) {
                if (dflag)
                        debug("could not map hardware address to IP address");
                return (1);
        }

        /*
         * Find the IP address on the right net.
         */
        for (p = hp->h_addr_list; *p; p++) {
                (void) memcpy(&addr, *p, sizeof (ipaddr_t));
                for (ifdev = rdev->ifdev; ifdev != NULL; ifdev = ifdev->next) {
                        if (dflag) {
                                struct in_addr daddr;
                                ipaddr_t netnum;

                                netnum = htonl(ifdev->if_netnum);
                                (void) memcpy(&daddr, &netnum,
                                    sizeof (ipaddr_t));
                                if (ifdev->lunit == -1)
                                        debug("trying physical netnum %s"
                                            " mask %x", inet_ntoa(daddr),
                                            ifdev->if_netmask);
                                else
                                        debug("trying logical %d netnum %s"
                                            " mask %x", ifdev->lunit,
                                            inet_ntoa(daddr),
                                            ifdev->if_netmask);
                        }
                        if ((ntohl(addr.s_addr) & ifdev->if_netmask) ==
                            ifdev->if_netnum) {
                                /*
                                 * Return the correct IP address.
                                 */
                                (void) memcpy(ipp, &addr, sizeof (ipaddr_t));

                                /*
                                 * Return the interface's ipaddr
                                 */
                                (void) memcpy(ipaddr, &ifdev->ipaddr,
                                    sizeof (ipaddr_t));

                                return (0);
                        }
                }
        }

        if (dflag)
                debug("got host entry but no IP address on this net");
        return (1);
}

static int
strioctl(int fd, int cmd, int timout, int len, char *dp)
{
        struct  strioctl        si;

        si.ic_cmd = cmd;
        si.ic_timout = timout;
        si.ic_len = len;
        si.ic_dp = dp;
        return (ioctl(fd, I_STR, &si));
}

static void
usage(void)
{
        error("Usage:  %s [ -ad ] device unit", cmdname);
}

static void
syserr(const char *s)
{
        char buf[256];
        int status = 1;

        (void) snprintf(buf, sizeof (buf), "%s: %s", s, strerror(errno));
        (void) fprintf(stderr, "%s:  %s\n", cmdname, buf);
        syslog(LOG_ERR, "%s", buf);
        thr_exit(&status);
}

static void
error(const char *fmt, ...)
{
        char buf[256];
        va_list ap;
        int status = 1;

        va_start(ap, fmt);
        (void) vsprintf(buf, fmt, ap);
        va_end(ap);
        (void) fprintf(stderr, "%s:  %s\n", cmdname, buf);
        syslog(LOG_ERR, buf);
        thr_exit(&status);
}

/*PRINTFLIKE1*/
static void
debug(char *fmt, ...)
{
        va_list ap;

        (void) mutex_lock(&debug_mutex);
        va_start(ap, fmt);
        (void) fprintf(stderr, "%s:[%u]  ", cmdname, thr_self());
        (void) vfprintf(stderr, fmt, ap);
        (void) fprintf(stderr, "\n");
        va_end(ap);
        (void) mutex_unlock(&debug_mutex);
}