[thirdparty/dhcp.git] / common / dlpi.c

/* dlpi.c
 
   Data Link Provider Interface (DLPI) network interface code. */

/*
 * Copyright (c) 2009-2011 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 2004,2007 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1996-2003 by Internet Software Consortium
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *   Internet Systems Consortium, Inc.
 *   950 Charter Street
 *   Redwood City, CA 94063
 *   <info@isc.org>
 *   https://www.isc.org/
 *
 * This software was written for Internet Systems Consortium
 * by Eric James Negaard, <lmdejn@lmd.ericsson.se>.  To learn more about
 * Internet Systems Consortium, see ``https://www.isc.org''.
 *
 * Joost Mulders has also done considerable work in debugging the DLPI API
 * support on Solaris and getting this code to work properly on a variety
 * of different Solaris platforms.
 */

/*
 * Based largely in part to the existing NIT code in nit.c.
 *
 * This code has been developed and tested on sparc-based machines running
 * SunOS 5.5.1, with le and hme network interfaces.  It should be pretty
 * generic, though.
 */

/*
 * Implementation notes:
 *
 * I first tried to write this code to the "vanilla" DLPI 2.0 API.
 * It worked on a Sun Ultra-1 with a hme interface, but didn't work
 * on Sun SparcStation 5's with "le" interfaces (the packets sent out
 * via dlpiunitdatareq contained an Ethernet type of 0x0000 instead
 * of the expected 0x0800).
 *
 * Therefore I added the "DLPI_RAW" code which is a Sun extension to
 * the DLPI standard.  This code works on both of the above machines.
 * This is configurable in the OS-dependent include file by defining
 * USE_DLPI_RAW.
 *
 * It quickly became apparant that I should also use the "pfmod"
 * STREAMS module to cut down on the amount of user level packet
 * processing.  I don't know how widely available "pfmod" is, so it's
 * use is conditionally included. This is configurable in the
 * OS-dependent include file by defining USE_DLPI_PFMOD.
 *
 * A major quirk on the Sun's at least, is that no packets seem to get
 * sent out the interface until six seconds after the interface is
 * first "attached" to [per system reboot] (it's actually from when
 * the interface is attached, not when it is plumbed, so putting a
 * sleep into the dhclient-script at PREINIT time doesn't help).  I
 * HAVE tried, without success to poll the fd to see when it is ready
 * for writing.  This doesn't help at all. If the sleeps are not done,
 * the initial DHCPREQUEST or DHCPDISCOVER never gets sent out, so
 * I've put them here, when register_send and register_receive are
 * called (split up into two three-second sleeps between the notices,
 * so that it doesn't seem like so long when you're watching :-).  The
 * amount of time to sleep is configurable in the OS-dependent include
 * file by defining DLPI_FIRST_SEND_WAIT to be the number of seconds
 * to sleep.
 */

/*
 * The Open Group Technical Standard can be found here:
 * http://www.opengroup.org/onlinepubs/009618899/index.htm
 *
 * The HP DLPI Programmer's Guide can be found here:
 * http://docs.hp.com/en/B2355-90139/index.html
 */

#include "dhcpd.h"

#if defined (USE_DLPI_SEND) || defined (USE_DLPI_RECEIVE) || \
    defined(USE_DLPI_HWADDR)

# include <sys/ioctl.h>
# include <sys/time.h>
# include <sys/dlpi.h>
# include <stropts.h>
# ifdef USE_DLPI_PFMOD
#  include <sys/pfmod.h>
# endif
#include <poll.h>
#include <errno.h>

# include <netinet/in_systm.h>
# include "includes/netinet/ip.h"
# include "includes/netinet/udp.h"
# include "includes/netinet/if_ether.h"

# ifdef USE_DLPI_PFMOD
#  ifdef USE_DLPI_RAW
#   define DLPI_MODNAME "DLPI+RAW+PFMOD"
#  else
#   define DLPI_MODNAME "DLPI+PFMOD"
#  endif
# else
#  ifdef USE_DLPI_RAW
#   define DLPI_MODNAME "DLPI+RAW"
#  else
#   define DLPI_MODNAME "DLPI"
#  endif
# endif

# ifndef ABS
#  define ABS(x) ((x) >= 0 ? (x) : 0-(x))
# endif

#if defined(USE_DLPI_PFMOD) || defined(USE_DLPI_RAW)
static int strioctl PROTO ((int fd, int cmd, int timeout, int len, char *dp));
#endif

#define DLPI_MAXDLBUF           8192    /* Buffer size */
#define DLPI_MAXDLADDR          1024    /* Max address size */
#define DLPI_DEVDIR             "/dev/" /* Device directory */

static int dlpiopen(const char *ifname);
static int dlpiunit PROTO ((char *ifname));
static int dlpiinforeq PROTO ((int fd));
static int dlpiphysaddrreq PROTO ((int fd, unsigned long addrtype));
static int dlpiattachreq PROTO ((int fd, unsigned long ppa));
static int dlpibindreq PROTO ((int fd, unsigned long sap, unsigned long max_conind,
                               unsigned long service_mode, unsigned long conn_mgmt,
                               unsigned long xidtest));
#if defined(UNUSED_DLPI_INTERFACE)
/* These functions are unused at present, but may be used at a later date.
 * defined out to avoid compiler warnings about unused static functions.
 */
static int dlpidetachreq PROTO ((int fd));
static int dlpiunbindreq PROTO ((int fd));
#endif
static int dlpiokack PROTO ((int fd, char *bufp));
static int dlpiinfoack PROTO ((int fd, char *bufp));
static int dlpiphysaddrack PROTO ((int fd, char *bufp));
static int dlpibindack PROTO ((int fd, char *bufp));
#if defined(USE_DLPI_SEND) || defined(USE_DLPI_RECEIVE)
/* These functions are not used if we're only sourcing the get_hw_addr()
 * function (for USE_SOCKETS).
 */
static int dlpiunitdatareq PROTO ((int fd, unsigned char *addr,
                                   int addrlen, unsigned long minpri,
                                   unsigned long maxpri, unsigned char *data,
                                   int datalen));
static int dlpiunitdataind PROTO ((int fd,
                                   unsigned char *dstaddr,
                                   unsigned long *dstaddrlen,
                                   unsigned char *srcaddr,
                                   unsigned long *srcaddrlen,
                                   unsigned long *grpaddr,
                                   unsigned char *data,
                                   int datalen));
#endif /* !USE_DLPI_HWADDR: USE_DLPI_SEND || USE_DLPI_RECEIVE */
static int      expected PROTO ((unsigned long prim, union DL_primitives *dlp,
                                  int msgflags));
static int      strgetmsg PROTO ((int fd, struct strbuf *ctlp,
                                  struct strbuf *datap, int *flagsp,
                                  char *caller));

/* Reinitializes the specified interface after an address change.   This
   is not required for packet-filter APIs. */

#ifdef USE_DLPI_SEND
void if_reinitialize_send (info)
        struct interface_info *info;
{
}
#endif

#ifdef USE_DLPI_RECEIVE
void if_reinitialize_receive (info)
        struct interface_info *info;
{
}
#endif

/* Called by get_interface_list for each interface that's discovered.
   Opens a packet filter for each interface and adds it to the select
   mask. */

int if_register_dlpi (info)
        struct interface_info *info;
{
        int sock;
        int unit;
        long buf [DLPI_MAXDLBUF];
        union DL_primitives *dlp;

        dlp = (union DL_primitives *)buf;

        /* Open a DLPI device */
        if ((sock = dlpiopen (info -> name)) < 0) {
            log_fatal ("Can't open DLPI device for %s: %m", info -> name);
        }

        /*
         * Submit a DL_INFO_REQ request, to find the dl_mac_type and 
         * dl_provider_style
         */
        if (dlpiinforeq(sock) < 0 || dlpiinfoack(sock, (char *)buf) < 0) {
            log_fatal ("Can't get DLPI MAC type for %s: %m", info -> name);
        } else {
            switch (dlp -> info_ack.dl_mac_type) {
              case DL_CSMACD: /* IEEE 802.3 */
              case DL_ETHER:
                info -> hw_address.hbuf [0] = HTYPE_ETHER;
                break;
              /* adding token ring 5/1999 - mayer@ping.at  */ 
              case DL_TPR:
                info -> hw_address.hbuf [0] = HTYPE_IEEE802;
                break;
              case DL_FDDI:
                info -> hw_address.hbuf [0] = HTYPE_FDDI;
                break;
              default:
                log_fatal("%s: unsupported DLPI MAC type %lu", info->name,
                          (unsigned long)dlp->info_ack.dl_mac_type);
                break;
            }
            /*
             * copy the sap length and broadcast address of this interface
             * to interface_info. This fixes nothing but seemed nicer than to
             * assume -2 and ffffff.
             */
            info -> dlpi_sap_length = dlp -> info_ack.dl_sap_length;
            info -> dlpi_broadcast_addr.hlen = 
             dlp -> info_ack.dl_brdcst_addr_length;
            memcpy (info -> dlpi_broadcast_addr.hbuf, 
             (char *)dlp + dlp -> info_ack.dl_brdcst_addr_offset, 
             dlp -> info_ack.dl_brdcst_addr_length);
        }

        if (dlp -> info_ack.dl_provider_style == DL_STYLE2) {
            /*
             * Attach to the device.  If this fails, the device
             * does not exist.
             */
            unit = dlpiunit (info -> name);
        
            if (dlpiattachreq (sock, unit) < 0
                || dlpiokack (sock, (char *)buf) < 0) {
                log_fatal ("Can't attach DLPI device for %s: %m", info -> name);
            }
        }

        /*
         * Bind to the IP service access point (SAP), connectionless (CLDLS).
         */
        if (dlpibindreq (sock, ETHERTYPE_IP, 0, DL_CLDLS, 0, 0) < 0
            || dlpibindack (sock, (char *)buf) < 0) {
            log_fatal ("Can't bind DLPI device for %s: %m", info -> name);
        }

        /*
         * Submit a DL_PHYS_ADDR_REQ request, to find
         * the hardware address
         */
        if (dlpiphysaddrreq (sock, DL_CURR_PHYS_ADDR) < 0
            || dlpiphysaddrack (sock, (char *)buf) < 0) {
            log_fatal ("Can't get DLPI hardware address for %s: %m",
                   info -> name);
        }

        info -> hw_address.hlen = dlp -> physaddr_ack.dl_addr_length + 1;
        memcpy (&info -> hw_address.hbuf [1],
                (char *)buf + dlp -> physaddr_ack.dl_addr_offset,
                dlp -> physaddr_ack.dl_addr_length);

#ifdef USE_DLPI_RAW
        if (strioctl (sock, DLIOCRAW, INFTIM, 0, 0) < 0) {
            log_fatal ("Can't set DLPI RAW mode for %s: %m",
                   info -> name);
        }
#endif

#ifdef USE_DLPI_PFMOD
        if (ioctl (sock, I_PUSH, "pfmod") < 0) {
            log_fatal ("Can't push packet filter onto DLPI for %s: %m",
                   info -> name);
        }
#endif

        return sock;
}

#if defined(USE_DLPI_PFMOD) || defined(USE_DLPI_RAW)
static int
strioctl (fd, cmd, timeout, len, dp)
int fd;
int cmd;
int timeout;
int len;
char *dp;
{
    struct strioctl sio;
    int rslt;

    sio.ic_cmd = cmd;
    sio.ic_timout = timeout;
    sio.ic_len = len;
    sio.ic_dp = dp;

    if ((rslt = ioctl (fd, I_STR, &sio)) < 0) {
        return rslt;
    } else {
        return sio.ic_len;
    }
}
#endif /* USE_DPI_PFMOD || USE_DLPI_RAW */

#ifdef USE_DLPI_SEND
void if_register_send (info)
        struct interface_info *info;
{
        /* If we're using the DLPI API for sending and receiving,
           we don't need to register this interface twice. */
#ifndef USE_DLPI_RECEIVE
# ifdef USE_DLPI_PFMOD
        struct packetfilt pf;
# endif

        info -> wfdesc = if_register_dlpi (info);

# ifdef USE_DLPI_PFMOD
        /* Set up an PFMOD filter that rejects everything... */
        pf.Pf_Priority = 0;
        pf.Pf_FilterLen = 1;
        pf.Pf_Filter [0] = ENF_PUSHZERO;

        /* Install the filter */
        if (strioctl (info -> wfdesc, PFIOCSETF, INFTIM,
                      sizeof (pf), (char *)&pf) < 0) {
            log_fatal ("Can't set PFMOD send filter on %s: %m", info -> name);
        }

# endif /* USE_DLPI_PFMOD */
#else /* !defined (USE_DLPI_RECEIVE) */
        /*
         * If using DLPI for both send and receive, simply re-use
         * the read file descriptor that was set up earlier.
         */
        info -> wfdesc = info -> rfdesc;
#endif

        if (!quiet_interface_discovery)
                log_info ("Sending on   DLPI/%s/%s%s%s",
                      info -> name,
                      print_hw_addr (info -> hw_address.hbuf [0],
                                     info -> hw_address.hlen - 1,
                                     &info -> hw_address.hbuf [1]),
                      (info -> shared_network ? "/" : ""),
                      (info -> shared_network ?
                       info -> shared_network -> name : ""));

#ifdef DLPI_FIRST_SEND_WAIT
/* See the implementation notes at the beginning of this file */
# ifdef USE_DLPI_RECEIVE
        sleep (DLPI_FIRST_SEND_WAIT - (DLPI_FIRST_SEND_WAIT / 2));
# else
        sleep (DLPI_FIRST_SEND_WAIT);
# endif
#endif
}

void if_deregister_send (info)
        struct interface_info *info;
{
        /* If we're using the DLPI API for sending and receiving,
           we don't need to register this interface twice. */
#ifndef USE_DLPI_RECEIVE
        close (info -> wfdesc);
#endif
        info -> wfdesc = -1;

        if (!quiet_interface_discovery)
                log_info ("Disabling output on DLPI/%s/%s%s%s",
                      info -> name,
                      print_hw_addr (info -> hw_address.hbuf [0],
                                     info -> hw_address.hlen - 1,
                                     &info -> hw_address.hbuf [1]),
                      (info -> shared_network ? "/" : ""),
                      (info -> shared_network ?
                       info -> shared_network -> name : ""));
}
#endif /* USE_DLPI_SEND */

#ifdef USE_DLPI_RECEIVE
/* Packet filter program...
   XXX Changes to the filter program may require changes to the constant
   offsets used in if_register_send to patch the NIT program! XXX */

void if_register_receive (info)
        struct interface_info *info;
{
#ifdef USE_DLPI_PFMOD
        struct packetfilt pf;
        struct ip iphdr;
        u_int16_t offset;
#endif

        /* Open a DLPI device and hang it on this interface... */
        info -> rfdesc = if_register_dlpi (info);

#ifdef USE_DLPI_PFMOD
        /* Set up the PFMOD filter program. */
        /* XXX Unlike the BPF filter program, this one won't work if the
           XXX IP packet is fragmented or if there are options on the IP
           XXX header. */
        pf.Pf_Priority = 0;
        pf.Pf_FilterLen = 0;

#if defined (USE_DLPI_RAW)
# define ETHER_H_PREFIX (14) /* sizeof (ethernet_header) */
    /*
     * ethertype == ETHERTYPE_IP
     */
    offset = 12;
    pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + (offset / 2);
    pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT | ENF_CAND;
    pf.Pf_Filter [pf.Pf_FilterLen++] = htons (ETHERTYPE_IP);
# else
# define ETHER_H_PREFIX (0)
# endif /* USE_DLPI_RAW */
        /*
         * The packets that will be received on this file descriptor
         * will be IP packets (due to the SAP that was specified in
         * the dlbind call).  There will be no ethernet header.
         * Therefore, setup the packet filter to check the protocol
         * field for UDP, and the destination port number equal
         * to the local port.  All offsets are relative to the start
         * of an IP packet.
         */

        /*
         * BOOTPS destination port
         */
        offset = ETHER_H_PREFIX + sizeof (iphdr) + sizeof (u_int16_t);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + (offset / 2);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT | ENF_CAND;
        pf.Pf_Filter [pf.Pf_FilterLen++] = local_port;

        /*
         * protocol should be udp. this is a byte compare, test for
         * endianess.
         */
        offset = ETHER_H_PREFIX + ((u_int8_t *)&(iphdr.ip_p) - (u_int8_t *)&iphdr);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + (offset / 2);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT | ENF_AND;
        pf.Pf_Filter [pf.Pf_FilterLen++] = htons (0x00FF);
        pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT | ENF_CAND;
      pf.Pf_Filter [pf.Pf_FilterLen++] = htons (IPPROTO_UDP);

        /* Install the filter... */
        if (strioctl (info -> rfdesc, PFIOCSETF, INFTIM,
                      sizeof (pf), (char *)&pf) < 0) {
            log_fatal ("Can't set PFMOD receive filter on %s: %m", info -> name);
        }
#endif /* USE_DLPI_PFMOD */

        if (!quiet_interface_discovery)
                log_info ("Listening on DLPI/%s/%s%s%s",
                      info -> name,
                      print_hw_addr (info -> hw_address.hbuf [0],
                                     info -> hw_address.hlen - 1,
                                     &info -> hw_address.hbuf [1]),
                      (info -> shared_network ? "/" : ""),
                      (info -> shared_network ?
                       info -> shared_network -> name : ""));

#ifdef DLPI_FIRST_SEND_WAIT
/* See the implementation notes at the beginning of this file */
# ifdef USE_DLPI_SEND
        sleep (DLPI_FIRST_SEND_WAIT / 2);
# else
        sleep (DLPI_FIRST_SEND_WAIT);
# endif
#endif
}

void if_deregister_receive (info)
        struct interface_info *info;
{
        /* If we're using the DLPI API for sending and receiving,
           we don't need to register this interface twice. */
#ifndef USE_DLPI_SEND
        close (info -> rfdesc);
#endif
        info -> rfdesc = -1;

        if (!quiet_interface_discovery)
                log_info ("Disabling input on DLPI/%s/%s%s%s",
                      info -> name,
                      print_hw_addr (info -> hw_address.hbuf [0],
                                     info -> hw_address.hlen - 1,
                                     &info -> hw_address.hbuf [1]),
                      (info -> shared_network ? "/" : ""),
                      (info -> shared_network ?
                       info -> shared_network -> name : ""));
}
#endif /* USE_DLPI_RECEIVE */

#ifdef USE_DLPI_SEND
ssize_t send_packet (interface, packet, raw, len, from, to, hto)
        struct interface_info *interface;
        struct packet *packet;
        struct dhcp_packet *raw;
        size_t len;
        struct in_addr from;
        struct sockaddr_in *to;
        struct hardware *hto;
{
#ifdef USE_DLPI_RAW
        double hh [32];
#endif
        double ih [1536 / sizeof (double)];
        unsigned char *dbuf = (unsigned char *)ih;
        unsigned dbuflen;
        unsigned char dstaddr [DLPI_MAXDLADDR];
        unsigned addrlen;
        int result;
        int fudge;

        if (!strcmp (interface -> name, "fallback"))
                return send_fallback (interface, packet, raw,
                                      len, from, to, hto);

        if (hto == NULL && interface->anycast_mac_addr.hlen)
                hto = &interface->anycast_mac_addr;

        dbuflen = 0;

        /* Assemble the headers... */
#ifdef USE_DLPI_RAW
        assemble_hw_header (interface, (unsigned char *)hh, &dbuflen, hto);
      if (dbuflen > sizeof hh)
              log_fatal ("send_packet: hh buffer too small.\n");
        fudge = dbuflen % 4; /* IP header must be word-aligned. */
        memcpy (dbuf + fudge, (unsigned char *)hh, dbuflen);
        dbuflen += fudge;
#else
        fudge = 0;
#endif
        assemble_udp_ip_header (interface, dbuf, &dbuflen, from.s_addr,
                                to -> sin_addr.s_addr, to -> sin_port,
                                (unsigned char *)raw, len);

        /* Copy the data into the buffer (yuk). */
        memcpy (dbuf + dbuflen, raw, len);
        dbuflen += len;

#ifdef USE_DLPI_RAW
        result = write (interface -> wfdesc, dbuf + fudge, dbuflen - fudge);
#else

        /*
         * Setup the destination address (DLSAP) in dstaddr 
         *
         * If sap_length < 0 we must deliver the DLSAP as phys+sap. 
         * If sap_length > 0 we must deliver the DLSAP as sap+phys.
         *
         * sap = Service Access Point == ETHERTYPE_IP
         * sap + datalink address is called DLSAP in dlpi speak.
         */
        { /* ENCODE DLSAP */
          unsigned char phys [DLPI_MAXDLADDR];
          unsigned char sap [4];
          int sap_len = interface -> dlpi_sap_length;
          int phys_len = interface -> hw_address.hlen - 1;

          /* sap = htons (ETHERTYPE_IP) kludge */
          memset (sap, 0, sizeof (sap));
# if (BYTE_ORDER == LITTLE_ENDIAN)
          sap [0] = 0x00;
          sap [1] = 0x08;
# else
          sap [0] = 0x08;
          sap [1] = 0x00;
# endif

        if (hto && hto -> hlen == interface -> hw_address.hlen)
             memcpy ( phys, (char *) &hto -> hbuf [1], phys_len);
          else 
             memcpy ( phys, interface -> dlpi_broadcast_addr.hbuf, 
              interface -> dlpi_broadcast_addr.hlen);

          if (sap_len < 0) { 
             memcpy ( dstaddr, phys, phys_len);
             memcpy ( (char *) &dstaddr [phys_len], sap, ABS (sap_len));
          }
          else {
             memcpy ( dstaddr, (void *) sap, sap_len);
             memcpy ( (char *) &dstaddr [sap_len], phys, phys_len);
          }
        addrlen = phys_len + ABS (sap_len);
      } /* ENCODE DLSAP */

        result = dlpiunitdatareq (interface -> wfdesc, dstaddr, addrlen,
                                  0, 0, dbuf, dbuflen);
#endif /* USE_DLPI_RAW */
        if (result < 0)
                log_error ("send_packet: %m");
        return result;
}
#endif /* USE_DLPI_SEND */

#ifdef USE_DLPI_RECEIVE
ssize_t receive_packet (interface, buf, len, from, hfrom)
        struct interface_info *interface;
        unsigned char *buf;
        size_t len;
        struct sockaddr_in *from;
        struct hardware *hfrom;
{
        unsigned char dbuf [1536];
        unsigned char srcaddr [DLPI_MAXDLADDR];
        unsigned long srcaddrlen;
        int length = 0;
        int offset = 0;
        int bufix = 0;
        unsigned paylen;
        
#ifdef USE_DLPI_RAW
        length = read (interface -> rfdesc, dbuf, sizeof (dbuf));
#else   
        length = dlpiunitdataind (interface -> rfdesc, (unsigned char *)NULL,
                                  (unsigned long *)NULL, srcaddr, &srcaddrlen,
                                  (unsigned long *)NULL, dbuf, sizeof (dbuf));
#endif

        if (length <= 0) {
            log_error("receive_packet: %m");
            return length;
        }

# if !defined (USE_DLPI_RAW)
        /*
         * Copy the sender's hw address into hfrom
         * If sap_len < 0 the DLSAP is as phys+sap.
         * If sap_len > 0 the DLSAP is as sap+phys.
         *
         * sap is discarded here.
         */
        { /* DECODE DLSAP */
          int sap_len = interface -> dlpi_sap_length;
          int phys_len = interface -> hw_address.hlen - 1;

          if (hfrom && (srcaddrlen == ABS (sap_len) + phys_len )) {
            hfrom -> hbuf [0] = interface -> hw_address.hbuf [0];
            hfrom -> hlen = interface -> hw_address.hlen;
            
            if (sap_len < 0) {
              memcpy ((char *) &hfrom -> hbuf [1], srcaddr, phys_len);
            }
            else {
              memcpy((char *)&hfrom->hbuf[1], srcaddr + sap_len, phys_len);
            }
          } 
          else if (hfrom) {
            memset (hfrom, '\0', sizeof *hfrom);
          }
        } /* DECODE_DLSAP */

# endif /* !defined (USE_DLPI_RAW) */

        /* Decode the IP and UDP headers... */
        bufix = 0;
#ifdef USE_DLPI_RAW
        /* Decode the physical header... */
        offset = decode_hw_header (interface, dbuf, bufix, hfrom);

        /* If a physical layer checksum failed (dunno of any
           physical layer that supports this, but WTH), skip this
           packet. */
        if (offset < 0) {
                return 0;
        }
        bufix += offset;
        length -= offset;
#endif
        offset = decode_udp_ip_header (interface, dbuf, bufix,
                                       from, length, &paylen);

        /*
         * If the IP or UDP checksum was bad, skip the packet...
         *
         * Note: this happens all the time when writing packets via the
         * fallback socket.  The packet received by streams does not have
         * the IP or UDP checksums filled in, as those are calculated by
         * the hardware.
         */
        if (offset < 0) {
                return 0;
        }

        bufix += offset;
        length -= offset;

        if (length < paylen)
                log_fatal("Internal inconsistency at %s:%d.", MDL);

        /* Copy out the data in the packet... */
        memcpy(buf, &dbuf [bufix], paylen);
        return paylen;
}
#endif

/* Common DLPI routines ...
 *
 * Written by Eric James Negaard, <lmdejn@lmd.ericsson.se>
 *
 * Based largely in part to the example code contained in the document
 * "How to Use the STREAMS Data Link Provider Interface (DLPI)", written
 * by Neal Nuckolls of SunSoft Internet Engineering.
 * 
 * This code has been developed and tested on sparc-based machines running
 * SunOS 5.5.1, with le and hme network interfaces.  It should be pretty
 * generic, though.
 * 
 * The usual disclaimers apply.  This code works for me.  Don't blame me
 * if it makes your machine or network go down in flames.  That taken
 * into consideration, use this code as you wish.  If you make usefull
 * modifications I'd appreciate hearing about it.
 */

#define DLPI_MAXWAIT            15      /* Max timeout */


/*
 * Parse an interface name and extract the unit number
 */

static int dlpiunit (ifname)
        char *ifname;
{
        char *cp;
        int unit;
        
        if (!ifname) {
                return 0;
        }
        
        /* Advance to the end of the name */
        cp = ifname;
        while (*cp) cp++;
        /* Back up to the start of the first digit */
        while ((*(cp-1) >= '0' && *(cp-1) <= '9') || *(cp - 1) == ':') cp--;
        
        /* Convert the unit number */
        unit = 0;
        while (*cp >= '0' && *cp <= '9') {
                unit *= 10;
                unit += (*cp++ - '0');
        }
        
        return unit;
}

/*
 * dlpiopen - open the DLPI device for a given interface name
 */
static int
dlpiopen(const char *ifname) {
        char devname [50];
        char *dp;
        const char *cp, *ep;
        
        if (!ifname) {
                return -1;
        }
        
        /* Open a DLPI device */
        if (*ifname == '/') {
                dp = devname;
        } else {
                /* Prepend the device directory */
                memcpy (devname, DLPI_DEVDIR, strlen (DLPI_DEVDIR));
                dp = &devname [strlen (DLPI_DEVDIR)];
        }

        /* Find the end of the interface name */
        ep = cp = ifname;
        while (*ep)
                ep++;
        /* And back up to the first digit (unit number) */
        while ((*(ep - 1) >= '0' && *(ep - 1) <= '9') || *(ep - 1) == ':')
                ep--;
        
        /* Copy everything up to the unit number */
        while (cp < ep) {
                *dp++ = *cp++;
        }
        *dp = '\0';
        
        return open (devname, O_RDWR, 0);
}

/*
 * dlpiinforeq - request information about the data link provider.
 */

static int dlpiinforeq (fd)
        int fd;
{
        dl_info_req_t info_req;
        struct strbuf ctl;
        int flags;
        
        info_req.dl_primitive = DL_INFO_REQ;
        
        ctl.maxlen = 0;
        ctl.len = sizeof (info_req);
        ctl.buf = (char *)&info_req;
        
        flags = RS_HIPRI;
        
        return putmsg (fd, &ctl, (struct strbuf *)NULL, flags);
}

/*
 * dlpiphysaddrreq - request the current physical address.
 */
static int dlpiphysaddrreq (fd, addrtype)
        int fd;
        unsigned long addrtype;
{
        dl_phys_addr_req_t physaddr_req;
        struct strbuf ctl;
        int flags;
        
        physaddr_req.dl_primitive = DL_PHYS_ADDR_REQ;
        physaddr_req.dl_addr_type = addrtype;
        
        ctl.maxlen = 0;
        ctl.len = sizeof (physaddr_req);
        ctl.buf = (char *)&physaddr_req;
        
        flags = RS_HIPRI;
        
        return putmsg (fd, &ctl, (struct strbuf *)NULL, flags);
}

/*
 * dlpiattachreq - send a request to attach to a specific unit.
 */
static int dlpiattachreq (fd, ppa)
        unsigned long ppa;
        int fd;
{
        dl_attach_req_t attach_req;
        struct strbuf ctl;
        int flags;
        
        attach_req.dl_primitive = DL_ATTACH_REQ;
        attach_req.dl_ppa = ppa;
        
        ctl.maxlen = 0;
        ctl.len = sizeof (attach_req);
        ctl.buf = (char *)&attach_req;
        
        flags = 0;
        
        return putmsg (fd, &ctl, (struct strbuf*)NULL, flags);
}

/*
 * dlpibindreq - send a request to bind to a specific SAP address.
 */
static int dlpibindreq (fd, sap, max_conind, service_mode, conn_mgmt, xidtest)
        unsigned long sap;
        unsigned long max_conind;
        unsigned long service_mode;
        unsigned long conn_mgmt;
        unsigned long xidtest;
        int fd;
{
        dl_bind_req_t bind_req;
        struct strbuf ctl;
        int flags;
        
        bind_req.dl_primitive = DL_BIND_REQ;
        bind_req.dl_sap = sap;
        bind_req.dl_max_conind = max_conind;
        bind_req.dl_service_mode = service_mode;
        bind_req.dl_conn_mgmt = conn_mgmt;
        bind_req.dl_xidtest_flg = xidtest;
        
        ctl.maxlen = 0;
        ctl.len = sizeof (bind_req);
        ctl.buf = (char *)&bind_req;
        
        flags = 0;
        
        return putmsg (fd, &ctl, (struct strbuf*)NULL, flags);
}

#if defined(UNUSED_DLPI_INTERFACE)
/*
 * dlpiunbindreq - send a request to unbind.  This function is not actually
 *      used by ISC DHCP, but is included for completeness in case it is
 *      ever required for new work.
 */
static int dlpiunbindreq (fd)
        int fd;
{
        dl_unbind_req_t unbind_req;
        struct strbuf ctl;
        int flags;
        
        unbind_req.dl_primitive = DL_UNBIND_REQ;
        
        ctl.maxlen = 0;
        ctl.len = sizeof (unbind_req);
        ctl.buf = (char *)&unbind_req;
        
        flags = 0;
        
        return putmsg (fd, &ctl, (struct strbuf*)NULL, flags);
}


/*
 * dlpidetachreq - send a request to detach.  This function is not actually
 *      used by ISC DHCP, but is included for completeness in case it is
 *      ever required for new work.
 */
static int dlpidetachreq (fd)
        int fd;
{
        dl_detach_req_t detach_req;
        struct strbuf ctl;
        int flags;
        
        detach_req.dl_primitive = DL_DETACH_REQ;
        
        ctl.maxlen = 0;
        ctl.len = sizeof (detach_req);
        ctl.buf = (char *)&detach_req;
        
        flags = 0;
        
        return putmsg (fd, &ctl, (struct strbuf*)NULL, flags);
}
#endif /* UNUSED_DLPI_INTERFACE */


/*
 * dlpibindack - receive an ack to a dlbindreq.
 */
static int dlpibindack (fd, bufp)
        char *bufp;
        int fd;
{
        union DL_primitives *dlp;
        struct strbuf ctl;
        int flags;
        
        ctl.maxlen = DLPI_MAXDLBUF;
        ctl.len = 0;
        ctl.buf = bufp;

        if (strgetmsg (fd, &ctl,
                       (struct strbuf*)NULL, &flags, "dlpibindack") < 0) {
                return -1;
        }
        
        dlp = (union DL_primitives *)ctl.buf;
        
        if (expected (DL_BIND_ACK, dlp, flags) == -1) {
                return -1;
        }
        
        if (ctl.len < sizeof (dl_bind_ack_t)) {
                /* Returned structure is too short */
                return -1;
        }

        return 0;
}

/*
 * dlpiokack - general acknowledgement reception.
 */
static int dlpiokack (fd, bufp)
        char *bufp;
        int fd;
{
        union DL_primitives *dlp;
        struct strbuf ctl;
        int flags;
        
        ctl.maxlen = DLPI_MAXDLBUF;
        ctl.len = 0;
        ctl.buf = bufp;
        
        if (strgetmsg (fd, &ctl,
                       (struct strbuf*)NULL, &flags, "dlpiokack") < 0) {
                return -1;
        }
        
        dlp = (union DL_primitives *)ctl.buf;
        
        if (expected (DL_OK_ACK, dlp, flags) == -1) {
                return -1;
        }
        
        if (ctl.len < sizeof (dl_ok_ack_t)) {
                /* Returned structure is too short */
                return -1;
        }
        
        return 0;
}

/*
 * dlpiinfoack - receive an ack to a dlinforeq.
 */
static int dlpiinfoack (fd, bufp)
        char *bufp;
        int fd;
{
        union DL_primitives *dlp;
        struct strbuf ctl;
        int flags;
        
        ctl.maxlen = DLPI_MAXDLBUF;
        ctl.len = 0;
        ctl.buf = bufp;
        
        if (strgetmsg (fd, &ctl, (struct strbuf *)NULL, &flags,
                       "dlpiinfoack") < 0) {
                return -1;
        }
        
        dlp = (union DL_primitives *) ctl.buf;
        
        if (expected (DL_INFO_ACK, dlp, flags) == -1) {
                return -1;
        }
        
        if (ctl.len < sizeof (dl_info_ack_t)) {
                /* Returned structure is too short */
                return -1;
        }
        
        return 0;
}

/*
 * dlpiphysaddrack - receive an ack to a dlpiphysaddrreq.
 */
int dlpiphysaddrack (fd, bufp)
        char *bufp;
        int fd;
{
        union DL_primitives *dlp;
        struct strbuf ctl;
        int flags;
        
        ctl.maxlen = DLPI_MAXDLBUF;
        ctl.len = 0;
        ctl.buf = bufp;
        
        if (strgetmsg (fd, &ctl, (struct strbuf *)NULL, &flags,
                       "dlpiphysaddrack") < 0) {
                return -1;
        }

        dlp = (union DL_primitives *)ctl.buf;
        
        if (expected (DL_PHYS_ADDR_ACK, dlp, flags) == -1) {
                return -1;
        }

        if (ctl.len < sizeof (dl_phys_addr_ack_t)) {
                /* Returned structure is too short */
                return -1;
        }
        
        return 0;
}

#if defined(USE_DLPI_SEND) || defined(USE_DLPI_RECEIVE)
int dlpiunitdatareq (fd, addr, addrlen, minpri, maxpri, dbuf, dbuflen)
        int fd;
        unsigned char *addr;
        int addrlen;
        unsigned long minpri;
        unsigned long maxpri;
        unsigned char *dbuf;
        int dbuflen;
{
        long buf [DLPI_MAXDLBUF];
        union DL_primitives *dlp;
        struct strbuf ctl, data;
        
        /* Set up the control information... */
        dlp = (union DL_primitives *)buf;
        dlp -> unitdata_req.dl_primitive = DL_UNITDATA_REQ;
        dlp -> unitdata_req.dl_dest_addr_length = addrlen;
        dlp -> unitdata_req.dl_dest_addr_offset = sizeof (dl_unitdata_req_t);
        dlp -> unitdata_req.dl_priority.dl_min = minpri;
        dlp -> unitdata_req.dl_priority.dl_max = maxpri;

        /* Append the destination address */
        memcpy ((char *)buf + dlp -> unitdata_req.dl_dest_addr_offset,
                addr, addrlen);
        
        ctl.maxlen = 0;
        ctl.len = dlp -> unitdata_req.dl_dest_addr_offset + addrlen;
        ctl.buf = (char *)buf;

        data.maxlen = 0;
        data.buf = (char *)dbuf;
        data.len = dbuflen;

        /* Send the packet down the wire... */
        return putmsg (fd, &ctl, &data, 0);
}

static int dlpiunitdataind (fd, daddr, daddrlen,
                            saddr, saddrlen, grpaddr, dbuf, dlen)
        int fd;
        unsigned char *daddr;
        unsigned long *daddrlen;
        unsigned char *saddr;
        unsigned long *saddrlen;
        unsigned long *grpaddr;
        unsigned char *dbuf;
        int dlen;
{
        long buf [DLPI_MAXDLBUF];
        union DL_primitives *dlp;
        struct strbuf ctl, data;
        int flags = 0;
        int result;

        /* Set up the msg_buf structure... */
        dlp = (union DL_primitives *)buf;
        dlp -> unitdata_ind.dl_primitive = DL_UNITDATA_IND;

        ctl.maxlen = DLPI_MAXDLBUF;
        ctl.len = 0;
        ctl.buf = (char *)buf;

        data.maxlen = dlen;
        data.len = 0;
        data.buf = (char *)dbuf;

        result = getmsg (fd, &ctl, &data, &flags);

        if (result < 0) {
                log_debug("dlpiunitdataind: %m");
                return -1;
        }

        if (ctl.len < sizeof (dl_unitdata_ind_t) ||
            dlp -> unitdata_ind.dl_primitive != DL_UNITDATA_IND) {
                return -1;
        }

        if (data.len <= 0) {
                return data.len;
        }

        /* Copy sender info */
        if (saddr) {
                memcpy (saddr,
                        (char *)buf + dlp -> unitdata_ind.dl_src_addr_offset,
                        dlp -> unitdata_ind.dl_src_addr_length);
        }
        if (saddrlen) {
                *saddrlen = dlp -> unitdata_ind.dl_src_addr_length;
        }

        /* Copy destination info */
        if (daddr) {
                memcpy (daddr,
                        (char *)buf + dlp -> unitdata_ind.dl_dest_addr_offset,
                        dlp -> unitdata_ind.dl_dest_addr_length);
        }
        if (daddrlen) {
                *daddrlen = dlp -> unitdata_ind.dl_dest_addr_length;
        }

        if (grpaddr) {
                *grpaddr = dlp -> unitdata_ind.dl_group_address;
        }

        return data.len;
}
#endif /* !USE_DLPI_HWADDR: USE_DLPI_RECEIVE || USE_DLPI_SEND */

/*
 * expected - see if we got what we wanted.
 */
static int expected (prim, dlp, msgflags)
        unsigned long prim;
        union DL_primitives *dlp;
        int msgflags;
{
        if (msgflags != RS_HIPRI) {
                /* Message was not M_PCPROTO */
                return -1;
        }

        if (dlp->dl_primitive != prim) {
                /* Incorrect/unexpected return message */
                return -1;
        }
        
        return 0;
}

/*
 * strgetmsg - get a message from a stream, with timeout.
 */
static int strgetmsg (fd, ctlp, datap, flagsp, caller)
        struct strbuf *ctlp, *datap;
        char *caller;
        int *flagsp;
        int fd;
{
        int result;
        struct pollfd pfd;
        int count;
        time_t now;
        time_t starttime;
        int to_msec;
        
        pfd.fd = fd;
        pfd.events = POLLPRI;   /* We're only interested in knowing
                                 * when we can receive the next high
                                 * priority message.
                                 */
        pfd.revents = 0;

        now = time (&starttime);
        while (now <= starttime + DLPI_MAXWAIT) {
                to_msec = ((starttime + DLPI_MAXWAIT) - now) * 1000;
                count = poll (&pfd, 1, to_msec);
                
                if (count == 0) {
                        /* log_fatal ("strgetmsg: timeout"); */
                        return -1;
                } else if (count < 0) {
                        if (errno == EAGAIN || errno == EINTR) {
                                time (&now);
                                continue;
                        } else {
                                /* log_fatal ("poll: %m"); */
                                return -1;
                        }
                } else {
                        break;
                }
        }

        /*
         * Set flags argument and issue getmsg ().
         */
        *flagsp = 0;
        if ((result = getmsg (fd, ctlp, datap, flagsp)) < 0) {
                return result;
        }

        /*
         * Check for MOREDATA and/or MORECTL.
         */
        if (result & (MORECTL|MOREDATA)) {
                return -1;
        }

        /*
         * Check for at least sizeof (long) control data portion.
         */
        if (ctlp -> len < sizeof (long)) {
                return -1;
        }

        return 0;
}

#if defined(USE_DLPI_SEND)
int can_unicast_without_arp (ip)
        struct interface_info *ip;
{
        return 1;
}

int can_receive_unicast_unconfigured (ip)
        struct interface_info *ip;
{
        return 1;
}

int supports_multiple_interfaces (ip)
        struct interface_info *ip;
{
        return 1;
}

void maybe_setup_fallback ()
{
        isc_result_t status;
        struct interface_info *fbi = (struct interface_info *)0;
        if (setup_fallback (&fbi, MDL)) {
                if_register_fallback (fbi);
                status = omapi_register_io_object ((omapi_object_t *)fbi,
                                                   if_readsocket, 0,
                                                   fallback_discard, 0, 0);
                if (status != ISC_R_SUCCESS)
                        log_fatal ("Can't register I/O handle for %s: %s",
                                   fbi -> name, isc_result_totext (status));
                interface_dereference (&fbi, MDL);
        }
}
#endif /* USE_DLPI_SEND */

void 
get_hw_addr(const char *name, struct hardware *hw) {
        int sock, unit;
        long buf[DLPI_MAXDLBUF];
        union DL_primitives *dlp;

        dlp = (union DL_primitives *)buf;

        /* 
         * Open a DLPI device.
         */
        sock = dlpiopen(name);
        if (sock < 0) {
                log_fatal("Can't open DLPI device for %s: %m", name);
        }

        /*
         * Submit a DL_INFO_REQ request, to find the dl_mac_type and 
         * dl_provider_style
         */
        if (dlpiinforeq(sock) < 0) {
            log_fatal("Can't request DLPI MAC type for %s: %m", name);
        }
        if (dlpiinfoack(sock, (char *)buf) < 0) {
            log_fatal("Can't get DLPI MAC type for %s: %m", name);
        }
        switch (dlp->info_ack.dl_mac_type) {
                case DL_CSMACD: /* IEEE 802.3 */
                case DL_ETHER:
                        hw->hbuf[0] = HTYPE_ETHER;
                        break;
                case DL_TPR:
                        hw->hbuf[0] = HTYPE_IEEE802;
                        break;
                case DL_FDDI:
                        hw->hbuf[0] = HTYPE_FDDI;
                        break;
                default:
                        log_fatal("%s: unsupported DLPI MAC type %lu", name,
                                  (unsigned long)dlp->info_ack.dl_mac_type);
        }

        if (dlp->info_ack.dl_provider_style == DL_STYLE2) {
                /*
                 * Attach to the device.  If this fails, the device
                 * does not exist.
                 */
                unit = dlpiunit((char *)name);

                if (dlpiattachreq(sock, unit) < 0 ||
                    dlpiokack(sock, (char *)buf) < 0) {
                        log_fatal("Can't attach DLPI device for %s: %m",
                                  name);
                }
        }

        /*
         * Submit a DL_PHYS_ADDR_REQ request, to find
         * the hardware address.
         */
        if (dlpiphysaddrreq(sock, DL_CURR_PHYS_ADDR) < 0) {
                log_fatal("Can't request DLPI hardware address for %s: %m",
                          name);
        }
        if (dlpiphysaddrack(sock, (char *)buf) < 0) {
                log_fatal("Can't get DLPI hardware address for %s: %m",
                          name);
        }
        if (dlp->physaddr_ack.dl_addr_length < sizeof(hw->hbuf)) {
                memcpy(hw->hbuf+1, 
                       (char *)buf + dlp->physaddr_ack.dl_addr_offset,
                       dlp->physaddr_ack.dl_addr_length);
                hw->hlen = dlp->physaddr_ack.dl_addr_length + 1;
        } else {
                memcpy(hw->hbuf+1, 
                       (char *)buf + dlp->physaddr_ack.dl_addr_offset,
                       sizeof(hw->hbuf)-1);
                hw->hlen = sizeof(hw->hbuf);
        }

        close(sock);
}
#endif /* USE_DLPI_SEND || USE_DLPI_RECEIVE || USE_DLPI_HWADDR */