/*
 * getether.c : get the ethernet address of an interface
 *
 * All of this code is quite system-specific.  As you may well
 * guess, it took a good bit of detective work to figure out!
 *
 * If you figure out how to do this on another system,
 * please let me know.  <gwr@mc.com>
 */

#include <sys/types.h>
#include <sys/socket.h>

#ifndef NO_UNISTD
#include <unistd.h>
#endif

#include <ctype.h>
#include <paths.h>
#include <string.h>
#include <syslog.h>

#include "getether.h"
#include "report.h"
#define EALEN 6

#if defined(ultrix) || (defined(__osf__) && defined(__alpha))
/*
 * This is really easy on Ultrix!  Thanks to
 * Harald Lundberg <hl@tekla.fi> for this code.
 *
 * The code here is not specific to the Alpha, but that was the
 * only symbol we could find to identify DEC's version of OSF.
 * (Perhaps we should just define DEC in the Makefile... -gwr)
 */

#include <sys/ioctl.h>
#include <net/if.h>                             /* struct ifdevea */

getether(ifname, eap)
        char *ifname, *eap;
{
        int rc = -1;
        int fd;
        struct ifdevea phys;
        bzero(&phys, sizeof(phys));
        strcpy(phys.ifr_name, ifname);
        if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
                report(LOG_ERR, "getether: socket(INET,DGRAM) failed");
                return -1;
        }
        if (ioctl(fd, SIOCRPHYSADDR, &phys) < 0) {
                report(LOG_ERR, "getether: ioctl SIOCRPHYSADDR failed");
        } else {
                bcopy(&phys.current_pa[0], eap, EALEN);
                rc = 0;
        }
        close(fd);
        return rc;
}

#define GETETHER
#endif /* ultrix|osf1 */


#ifdef  SUNOS

#include <sys/sockio.h>
#include <sys/time.h>                   /* needed by net_if.h */
#include <net/nit_if.h>                 /* for NIOCBIND */
#include <net/if.h>                             /* for struct ifreq */

getether(ifname, eap)
        char *ifname;                           /* interface name from ifconfig structure */
        char *eap;                                      /* Ether address (output) */
{
        int rc = -1;

        struct ifreq ifrnit;
        int nit;

        bzero((char *) &ifrnit, sizeof(ifrnit));
        strlcpy(&ifrnit.ifr_name[0], ifname, IFNAMSIZ);

        nit = open("/dev/nit", 0);
        if (nit < 0) {
                report(LOG_ERR, "getether: open /dev/nit: %s",
                           get_errmsg());
                return rc;
        }
        do {
                if (ioctl(nit, NIOCBIND, &ifrnit) < 0) {
                        report(LOG_ERR, "getether: NIOCBIND on nit");
                        break;
                }
                if (ioctl(nit, SIOCGIFADDR, &ifrnit) < 0) {
                        report(LOG_ERR, "getether: SIOCGIFADDR on nit");
                        break;
                }
                bcopy(&ifrnit.ifr_addr.sa_data[0], eap, EALEN);
                rc = 0;
        } while (0);
        close(nit);
        return rc;
}

#define GETETHER
#endif /* SUNOS */


#if defined(__FreeBSD__) || defined(__NetBSD__)
/* Thanks to John Brezak <brezak@ch.hp.com> for this code. */
#include <sys/ioctl.h>
#include <sys/time.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>

int
getether(char *ifname, char *eap)
{
        int fd, rc = -1;
        int n;
        struct ifreq ibuf[16];
        struct ifconf ifc;
        struct ifreq *ifrp, *ifend;

        /* Fetch the interface configuration */
        fd = socket(AF_INET, SOCK_DGRAM, 0);
        if (fd < 0) {
                report(LOG_ERR, "getether: socket %s: %s", ifname, get_errmsg());
                return (fd);
        }
        ifc.ifc_len = sizeof(ibuf);
        ifc.ifc_buf = (caddr_t) ibuf;
        if (ioctl(fd, SIOCGIFCONF, (char *) &ifc) < 0 ||
                ifc.ifc_len < sizeof(struct ifreq)) {
                report(LOG_ERR, "getether: SIOCGIFCONF: %s", get_errmsg());
                goto out;
        }
        /* Search interface configuration list for link layer address. */
        ifrp = ibuf;
        ifend = (struct ifreq *) ((char *) ibuf + ifc.ifc_len);
        while (ifrp < ifend) {
                /* Look for interface */
                if (strcmp(ifname, ifrp->ifr_name) == 0 &&
                        ifrp->ifr_addr.sa_family == AF_LINK &&
                ((struct sockaddr_dl *) &ifrp->ifr_addr)->sdl_type == IFT_ETHER) {
                        bcopy(LLADDR((struct sockaddr_dl *) &ifrp->ifr_addr), eap, EALEN);
                        rc = 0;
                        break;
                }
                /* Bump interface config pointer */
                n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
                if (n < sizeof(*ifrp))
                        n = sizeof(*ifrp);
                ifrp = (struct ifreq *) ((char *) ifrp + n);
        }

  out:
        close(fd);
        return (rc);
}

#define GETETHER
#endif /* __NetBSD__ */


#ifdef  SVR4
/*
 * This is for "Streams TCP/IP" by Lachman Associates.
 * They sure made this cumbersome!  -gwr
 */

#include <sys/sockio.h>
#include <sys/dlpi.h>
#include <stropts.h>
#include <string.h>
#ifndef NULL
#define NULL 0
#endif

int
getether(ifname, eap)
        char *ifname;                           /* interface name from ifconfig structure */
        char *eap;                                      /* Ether address (output) */
{
        int rc = -1;
        char devname[32];
        char tmpbuf[sizeof(union DL_primitives) + 16];
        struct strbuf cbuf;
        int fd, flags;
        union DL_primitives *dlp;
        char *enaddr;
        int unit = -1;                          /* which unit to attach */

        snprintf(devname, sizeof(devname), "%s%s", _PATH_DEV, ifname);
        fd = open(devname, 2);
        if (fd < 0) {
                /* Try without the trailing digit. */
                char *p = devname + 5;
                while (isalpha(*p))
                        p++;
                if (isdigit(*p)) {
                        unit = *p - '0';
                        *p = '\0';
                }
                fd = open(devname, 2);
                if (fd < 0) {
                        report(LOG_ERR, "getether: open %s: %s",
                                   devname, get_errmsg());
                        return rc;
                }
        }
#ifdef  DL_ATTACH_REQ
        /*
         * If this is a "Style 2" DLPI, then we must "attach" first
         * to tell the driver which unit (board, port) we want.
         * For now, decide this based on the device name.
         * (Should do "info_req" and check dl_provider_style ...)
         */
        if (unit >= 0) {
                memset(tmpbuf, 0, sizeof(tmpbuf));
                dlp = (union DL_primitives *) tmpbuf;
                dlp->dl_primitive = DL_ATTACH_REQ;
                dlp->attach_req.dl_ppa = unit;
                cbuf.buf = tmpbuf;
                cbuf.len = DL_ATTACH_REQ_SIZE;
                if (putmsg(fd, &cbuf, NULL, 0) < 0) {
                        report(LOG_ERR, "getether: attach: putmsg: %s", get_errmsg());
                        goto out;
                }
                /* Recv the ack. */
                cbuf.buf = tmpbuf;
                cbuf.maxlen = sizeof(tmpbuf);
                flags = 0;
                if (getmsg(fd, &cbuf, NULL, &flags) < 0) {
                        report(LOG_ERR, "getether: attach: getmsg: %s", get_errmsg());
                        goto out;
                }
                /*
                 * Check the type, etc.
                 */
                if (dlp->dl_primitive == DL_ERROR_ACK) {
                        report(LOG_ERR, "getether: attach: dlpi_errno=%d, unix_errno=%d",
                                   dlp->error_ack.dl_errno,
                                   dlp->error_ack.dl_unix_errno);
                        goto out;
                }
                if (dlp->dl_primitive != DL_OK_ACK) {
                        report(LOG_ERR, "getether: attach: not OK or ERROR");
                        goto out;
                }
        } /* unit >= 0 */
#endif  /* DL_ATTACH_REQ */

        /*
         * Get the Ethernet address the same way the ARP module
         * does when it is pushed onto a new stream (bind).
         * One should instead be able just do a dl_info_req
         * but many drivers do not supply the hardware address
         * in the response to dl_info_req (they MUST supply it
         * for dl_bind_ack because the ARP module requires it).
         */
        memset(tmpbuf, 0, sizeof(tmpbuf));
        dlp = (union DL_primitives *) tmpbuf;
        dlp->dl_primitive = DL_BIND_REQ;
        dlp->bind_req.dl_sap = 0x8FF;   /* XXX - Unused SAP */
        cbuf.buf = tmpbuf;
        cbuf.len = DL_BIND_REQ_SIZE;
        if (putmsg(fd, &cbuf, NULL, 0) < 0) {
                report(LOG_ERR, "getether: bind: putmsg: %s", get_errmsg());
                goto out;
        }
        /* Recv the ack. */
        cbuf.buf = tmpbuf;
        cbuf.maxlen = sizeof(tmpbuf);
        flags = 0;
        if (getmsg(fd, &cbuf, NULL, &flags) < 0) {
                report(LOG_ERR, "getether: bind: getmsg: %s", get_errmsg());
                goto out;
        }
        /*
         * Check the type, etc.
         */
        if (dlp->dl_primitive == DL_ERROR_ACK) {
                report(LOG_ERR, "getether: bind: dlpi_errno=%d, unix_errno=%d",
                           dlp->error_ack.dl_errno,
                           dlp->error_ack.dl_unix_errno);
                goto out;
        }
        if (dlp->dl_primitive != DL_BIND_ACK) {
                report(LOG_ERR, "getether: bind: not OK or ERROR");
                goto out;
        }
        if (dlp->bind_ack.dl_addr_offset == 0) {
                report(LOG_ERR, "getether: bind: ack has no address");
                goto out;
        }
        if (dlp->bind_ack.dl_addr_length < EALEN) {
                report(LOG_ERR, "getether: bind: ack address truncated");
                goto out;
        }
        /*
         * Copy the Ethernet address out of the message.
         */
        enaddr = tmpbuf + dlp->bind_ack.dl_addr_offset;
        memcpy(eap, enaddr, EALEN);
        rc = 0;

  out:
        close(fd);
        return rc;
}

#define GETETHER
#endif /* SVR4 */


#ifdef  __linux__
/*
 * This is really easy on Linux!  This version (for linux)
 * written by Nigel Metheringham <nigelm@ohm.york.ac.uk> and
 * updated by Pauline Middelink <middelin@polyware.iaf.nl>
 *
 * The code is almost identical to the Ultrix code - however
 * the names are different to confuse the innocent :-)
 * Most of this code was stolen from the Ultrix bit above.
 */

#include <memory.h>
#include <sys/ioctl.h>
#include <net/if.h>             /* struct ifreq */
#include <sys/socketio.h>       /* Needed for IOCTL defs */

int
getether(ifname, eap)
        char *ifname, *eap;
{
        int rc = -1;
        int fd;
        struct ifreq phys;

        memset(&phys, 0, sizeof(phys));
        strcpy(phys.ifr_name, ifname);
        if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
                report(LOG_ERR, "getether: socket(INET,DGRAM) failed");
                return -1;
        }
        if (ioctl(fd, SIOCGIFHWADDR, &phys) < 0) {
                report(LOG_ERR, "getether: ioctl SIOCGIFHWADDR failed");
        } else {
                memcpy(eap, &phys.ifr_hwaddr.sa_data, EALEN);
                rc = 0;
        }
        close(fd);
        return rc;
}

#define GETETHER
#endif  /* __linux__ */


/* If we don't know how on this system, just return an error. */
#ifndef GETETHER
int
getether(ifname, eap)
        char *ifname, *eap;
{
        return -1;
}

#endif /* !GETETHER */

/*
 * Local Variables:
 * tab-width: 4
 * c-indent-level: 4
 * c-argdecl-indent: 4
 * c-continued-statement-offset: 4
 * c-continued-brace-offset: -4
 * c-label-offset: -4
 * c-brace-offset: 0
 * End:
 */