[libpcap] / pcap-dlpi.c

/*
 * Copyright (c) 1993, 1994, 1995, 1996, 1997
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * This code contributed by Atanu Ghosh (atanu@cs.ucl.ac.uk),
 * University College London, and subsequently modified by
 * Guy Harris (guy@alum.mit.edu), Mark Pizzolato
 * <List-tcpdump-workers@subscriptions.pizzolato.net>,
 * Mark C. Brown (mbrown@hp.com), and Sagun Shakya <Sagun.Shakya@Sun.COM>.
 */

/*
 * Packet capture routine for DLPI under SunOS 5, HP-UX 9/10/11, and AIX.
 *
 * Notes:
 *
 *    - The DLIOCRAW ioctl() is specific to SunOS.
 *
 *    - There is a bug in bufmod(7) such that setting the snapshot
 *      length results in data being left of the front of the packet.
 *
 *    - It might be desirable to use pfmod(7) to filter packets in the
 *      kernel when possible.
 *
 *    - An older version of the HP-UX DLPI Programmer's Guide, which
 *      I think was advertised as the 10.20 version, used to be available
 *      at
 *
 *            http://docs.hp.com/hpux/onlinedocs/B2355-90093/B2355-90093.html
 *
 *      but is no longer available; it can still be found at
 *
 *            http://h21007.www2.hp.com/dspp/files/unprotected/Drivers/Docs/Refs/B2355-90093.pdf
 *
 *      in PDF form.
 *
 *    - The HP-UX 10.x, 11.0, and 11i v1.6 version of the HP-UX DLPI
 *      Programmer's Guide, which I think was once advertised as the
 *      11.00 version is available at
 *
 *            http://docs.hp.com/en/B2355-90139/index.html
 *
 *    - The HP-UX 11i v2 version of the HP-UX DLPI Programmer's Guide
 *      is available at
 *
 *            http://docs.hp.com/en/B2355-90871/index.html
 *
 *    - All of the HP documents describe raw-mode services, which are
 *      what we use if DL_HP_RAWDLS is defined.  XXX - we use __hpux
 *      in some places to test for HP-UX, but use DL_HP_RAWDLS in
 *      other places; do we support any versions of HP-UX without
 *      DL_HP_RAWDLS?
 */

#ifndef lint
static const char rcsid[] _U_ =
    "@(#) $Header: /tcpdump/master/libpcap/pcap-dlpi.c,v 1.126 2008-04-10 00:50:34 guy Exp $ (LBL)";
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/types.h>
#include <sys/time.h>
#ifdef HAVE_SYS_BUFMOD_H
#include <sys/bufmod.h>
#endif
#include <sys/dlpi.h>
#ifdef HAVE_SYS_DLPI_EXT_H
#include <sys/dlpi_ext.h>
#endif
#ifdef HAVE_HPUX9
#include <sys/socket.h>
#endif
#ifdef DL_HP_PPA_REQ
#include <sys/stat.h>
#endif
#include <sys/stream.h>
#if defined(HAVE_SOLARIS) && defined(HAVE_SYS_BUFMOD_H)
#include <sys/systeminfo.h>
#endif

#ifdef HAVE_HPUX9
#include <net/if.h>
#endif

#include <ctype.h>
#ifdef HAVE_HPUX9
#include <nlist.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stropts.h>
#include <unistd.h>

#ifdef HAVE_LIMITS_H
#include <limits.h>
#else
#define INT_MAX         2147483647
#endif

#include "pcap-int.h"
#include "dlpisubs.h"

#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif

#ifndef PCAP_DEV_PREFIX
#ifdef _AIX
#define PCAP_DEV_PREFIX "/dev/dlpi"
#else
#define PCAP_DEV_PREFIX "/dev"
#endif
#endif

#define MAXDLBUF        8192

/* Forwards */
static char *split_dname(char *, int *, char *);
static int dl_doattach(int, int, char *);
#ifdef DL_HP_RAWDLS
static int dl_dohpuxbind(int, char *);
#endif
static int dlattachreq(int, bpf_u_int32, char *);
static int dlbindreq(int, bpf_u_int32, char *);
static int dlbindack(int, char *, char *, int *);
static int dlpromisconreq(int, bpf_u_int32, char *);
static int dlokack(int, const char *, char *, char *);
static int dlinforeq(int, char *);
static int dlinfoack(int, char *, char *);

#ifdef HAVE_DLPI_PASSIVE
static void dlpassive(int, char *);
#endif

#ifdef DL_HP_RAWDLS
static int dlrawdatareq(int, const u_char *, int);
#endif
static int recv_ack(int, int, const char *, char *, char *, int *);
static char *dlstrerror(bpf_u_int32);
static char *dlprim(bpf_u_int32);
#if defined(HAVE_SOLARIS) && defined(HAVE_SYS_BUFMOD_H)
static char *get_release(bpf_u_int32 *, bpf_u_int32 *, bpf_u_int32 *);
#endif
static int send_request(int, char *, int, char *, char *);
#ifdef HAVE_HPUX9
static int dlpi_kread(int, off_t, void *, u_int, char *);
#endif
#ifdef HAVE_DEV_DLPI
static int get_dlpi_ppa(int, const char *, int, char *);
#endif

/* XXX Needed by HP-UX (at least) */
static bpf_u_int32 ctlbuf[MAXDLBUF];
static struct strbuf ctl = {
        MAXDLBUF,
        0,
        (char *)ctlbuf
};

static int
pcap_read_dlpi(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
        int cc;
        u_char *bp;
        int flags;
        struct strbuf data;

        flags = 0;
        cc = p->cc;
        if (cc == 0) {
                data.buf = (char *)p->buffer + p->offset;
                data.maxlen = p->bufsize;
                data.len = 0;
                do {
                        /*
                         * Has "pcap_breakloop()" been called?
                         */
                        if (p->break_loop) {
                                /*
                                 * Yes - clear the flag that indicates
                                 * that it has, and return -2 to
                                 * indicate that we were told to
                                 * break out of the loop.
                                 */
                                p->break_loop = 0;
                                return (-2);
                        }
                        /*
                         * XXX - check for the DLPI primitive, which
                         * would be DL_HP_RAWDATA_IND on HP-UX
                         * if we're in raw mode?
                         */
                        if (getmsg(p->fd, &ctl, &data, &flags) < 0) {
                                /* Don't choke when we get ptraced */
                                switch (errno) {

                                case EINTR:
                                        cc = 0;
                                        continue;

                                case EAGAIN:
                                        return (0);
                                }
                                strlcpy(p->errbuf, pcap_strerror(errno),
                                    sizeof(p->errbuf));
                                return (-1);
                        }
                        cc = data.len;
                } while (cc == 0);
                bp = p->buffer + p->offset;
        } else
                bp = p->bp;

        return (pcap_process_pkts(p, callback, user, cnt, bp, cc));
}

static int
pcap_inject_dlpi(pcap_t *p, const void *buf, size_t size)
{
        int ret;

#if defined(DLIOCRAW)
        ret = write(p->fd, buf, size);
        if (ret == -1) {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
                    pcap_strerror(errno));
                return (-1);
        }
#elif defined(DL_HP_RAWDLS)
        if (p->send_fd < 0) {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                    "send: Output FD couldn't be opened");
                return (-1);
        }
        ret = dlrawdatareq(p->send_fd, buf, size);
        if (ret == -1) {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
                    pcap_strerror(errno));
                return (-1);
        }
        /*
         * putmsg() returns either 0 or -1; it doesn't indicate how
         * many bytes were written (presumably they were all written
         * or none of them were written).  OpenBSD's pcap_inject()
         * returns the number of bytes written, so, for API compatibility,
         * we return the number of bytes we were told to write.
         */
        ret = size;
#else /* no raw mode */
        /*
         * XXX - this is a pain, because you might have to extract
         * the address from the packet and use it in a DL_UNITDATA_REQ
         * request.  That would be dependent on the link-layer type.
         *
         * I also don't know what SAP you'd have to bind the descriptor
         * to, or whether you'd need separate "receive" and "send" FDs,
         * nor do I know whether you'd need different bindings for
         * D/I/X Ethernet and 802.3, or for {FDDI,Token Ring} plus
         * 802.2 and {FDDI,Token Ring} plus 802.2 plus SNAP.
         *
         * So, for now, we just return a "you can't send" indication,
         * and leave it up to somebody with a DLPI-based system lacking
         * both DLIOCRAW and DL_HP_RAWDLS to supply code to implement
         * packet transmission on that system.  If they do, they should
         * send it to us - but should not send us code that assumes
         * Ethernet; if the code doesn't work on non-Ethernet interfaces,
         * it should check "p->linktype" and reject the send request if
         * it's anything other than DLT_EN10MB.
         */
        strlcpy(p->errbuf, "send: Not supported on this version of this OS",
            PCAP_ERRBUF_SIZE);
        ret = -1;
#endif /* raw mode */
        return (ret);
}   

#ifndef DL_IPATM
#define DL_IPATM        0x12    /* ATM Classical IP interface */
#endif

#ifdef HAVE_SOLARIS
/*
 * For SunATM.
 */
#ifndef A_GET_UNITS
#define A_GET_UNITS     (('A'<<8)|118)
#endif /* A_GET_UNITS */
#ifndef A_PROMISCON_REQ
#define A_PROMISCON_REQ (('A'<<8)|121)
#endif /* A_PROMISCON_REQ */
#endif /* HAVE_SOLARIS */

static void
pcap_close_dlpi(pcap_t *p)
{
        pcap_close_common(p);
        if (p->send_fd >= 0)
                close(p->send_fd);
}

static int
pcap_activate_dlpi(pcap_t *p)
{
        register char *cp;
        int ppa;
#ifdef HAVE_SOLARIS
        int isatm = 0;
#endif
        register dl_info_ack_t *infop;
#ifdef HAVE_SYS_BUFMOD_H
        bpf_u_int32 ss;
#ifdef HAVE_SOLARIS
        register char *release;
        bpf_u_int32 osmajor, osminor, osmicro;
#endif
#endif
        bpf_u_int32 buf[MAXDLBUF];
        char dname[100];
#ifndef HAVE_DEV_DLPI
        char dname2[100];
#endif
        int status = PCAP_ERROR;

        p->fd = -1;     /* indicate that it hasn't been opened yet */
        p->send_fd = -1;

#ifdef HAVE_DEV_DLPI
        /*
        ** Remove any "/dev/" on the front of the device.
        */
        cp = strrchr(p->opt.source, '/');
        if (cp == NULL)
                strlcpy(dname, p->opt.source, sizeof(dname));
        else
                strlcpy(dname, cp + 1, sizeof(dname));

        /*
         * Split the device name into a device type name and a unit number;
         * chop off the unit number, so "dname" is just a device type name.
         */
        cp = split_dname(dname, &ppa, p->errbuf);
        if (cp == NULL) {
                status = PCAP_ERROR_NO_SUCH_DEVICE;
                goto bad;
        }
        *cp = '\0';

        /*
         * Use "/dev/dlpi" as the device.
         *
         * XXX - HP's DLPI Programmer's Guide for HP-UX 11.00 says that
         * the "dl_mjr_num" field is for the "major number of interface
         * driver"; that's the major of "/dev/dlpi" on the system on
         * which I tried this, but there may be DLPI devices that
         * use a different driver, in which case we may need to
         * search "/dev" for the appropriate device with that major
         * device number, rather than hardwiring "/dev/dlpi".
         */
        cp = "/dev/dlpi";
        if ((p->fd = open(cp, O_RDWR)) < 0) {
                if (errno == EPERM || errno == EACCES)
                        status = PCAP_ERROR_PERM_DENIED;
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                    "%s: %s", cp, pcap_strerror(errno));
                goto bad;
        }

#ifdef DL_HP_RAWDLS
        /*
         * XXX - HP-UX 10.20 and 11.xx don't appear to support sending and
         * receiving packets on the same descriptor - you need separate
         * descriptors for sending and receiving, bound to different SAPs.
         *
         * If the open fails, we just leave -1 in "p->send_fd" and reject
         * attempts to send packets, just as if, in pcap-bpf.c, we fail
         * to open the BPF device for reading and writing, we just try
         * to open it for reading only and, if that succeeds, just let
         * the send attempts fail.
         */
        p->send_fd = open(cp, O_RDWR);
#endif

        /*
         * Get a table of all PPAs for that device, and search that
         * table for the specified device type name and unit number.
         */
        ppa = get_dlpi_ppa(p->fd, dname, ppa, p->errbuf);
        if (ppa < 0) {
                status = ppa;
                goto bad;
        }
#else
        /*
         * If the device name begins with "/", assume it begins with
         * the pathname of the directory containing the device to open;
         * otherwise, concatenate the device directory name and the
         * device name.
         */
        if (*p->opt.source == '/')
                strlcpy(dname, p->opt.source, sizeof(dname));
        else
                snprintf(dname, sizeof(dname), "%s/%s", PCAP_DEV_PREFIX,
                    p->opt.source);

        /*
         * Get the unit number, and a pointer to the end of the device
         * type name.
         */
        cp = split_dname(dname, &ppa, p->errbuf);
        if (cp == NULL) {
                status = PCAP_ERROR_NO_SUCH_DEVICE;
                goto bad;
        }

        /*
         * Make a copy of the device pathname, and then remove the unit
         * number from the device pathname.
         */
        strlcpy(dname2, dname, sizeof(dname));
        *cp = '\0';

        /* Try device without unit number */
        if ((p->fd = open(dname, O_RDWR)) < 0) {
                if (errno != ENOENT) {
                        if (errno == EACCES)
                                status = PCAP_ERROR_PERM_DENIED;
                        snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: %s", dname,
                            pcap_strerror(errno));
                        goto bad;
                }

                /* Try again with unit number */
                if ((p->fd = open(dname2, O_RDWR)) < 0) {
                        if (errno == ENOENT) {
                                status = PCAP_ERROR_NO_SUCH_DEVICE;

                                /*
                                 * We provide an error message even
                                 * for this error, for diagnostic
                                 * purposes (so that, for example,
                                 * the app can show the message if the
                                 * user requests it).
                                 *
                                 * In it, we just report "No DLPI device
                                 * found" with the device name, so people
                                 * don't get confused and think, for example,
                                 * that if they can't capture on "lo0"
                                 * on Solaris the fix is to change libpcap
                                 * (or the application that uses it) to
                                 * look for something other than "/dev/lo0",
                                 * as the fix is to look for an operating
                                 * system other than Solaris - you just
                                 * *can't* capture on a loopback interface
                                 * on Solaris, the lack of a DLPI device
                                 * for the loopback interface is just a
                                 * symptom of that inability.
                                 */
                                snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                                    "%s: No DLPI device found", p->opt.source);
                        } else {
                                if (errno == EACCES)
                                        status = PCAP_ERROR_PERM_DENIED;
                                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: %s",
                                    dname2, pcap_strerror(errno));
                        }
                        goto bad;
                }
                /* XXX Assume unit zero */
                ppa = 0;
        }
#endif

        /*
        ** Attach if "style 2" provider
        */
        if (dlinforeq(p->fd, p->errbuf) < 0 ||
            dlinfoack(p->fd, (char *)buf, p->errbuf) < 0)
                goto bad;
        infop = &((union DL_primitives *)buf)->info_ack;
#ifdef HAVE_SOLARIS
        if (infop->dl_mac_type == DL_IPATM)
                isatm = 1;
#endif
        if (infop->dl_provider_style == DL_STYLE2) {
                status = dl_doattach(p->fd, ppa, p->errbuf);
                if (status < 0)
                        goto bad;
#ifdef DL_HP_RAWDLS
                if (p->send_fd >= 0) {
                        if (dl_doattach(p->send_fd, ppa, p->errbuf) < 0)
                                goto bad;
                }
#endif
        }

        if (p->opt.rfmon) {
                /*
                 * This device exists, but we don't support monitor mode
                 * any platforms that support DLPI.
                 */
                status = PCAP_ERROR_RFMON_NOTSUP;
                goto bad;
        }

#ifdef HAVE_DLPI_PASSIVE
        /*
         * Enable Passive mode to be able to capture on aggregated link.
         * Not supported in all Solaris versions.
         */
        dlpassive(p->fd, p->errbuf);
#endif
        /*
        ** Bind (defer if using HP-UX 9 or HP-UX 10.20 or later, totally
        ** skip if using SINIX)
        */
#if !defined(HAVE_HPUX9) && !defined(HAVE_HPUX10_20_OR_LATER) && !defined(sinix)
#ifdef _AIX
        /*
        ** AIX.
        ** According to IBM's AIX Support Line, the dl_sap value
        ** should not be less than 0x600 (1536) for standard Ethernet.
        ** However, we seem to get DL_BADADDR - "DLSAP addr in improper
        ** format or invalid" - errors if we use 1537 on the "tr0"
        ** device, which, given that its name starts with "tr" and that
        ** it's IBM, probably means a Token Ring device.  (Perhaps we
        ** need to use 1537 on "/dev/dlpi/en" because that device is for
        ** D/I/X Ethernet, the "SAP" is actually an Ethernet type, and
        ** it rejects invalid Ethernet types.)
        **
        ** So if 1537 fails, we try 2, as Hyung Sik Yoon of IBM Korea
        ** says that works on Token Ring (he says that 0 does *not*
        ** work; perhaps that's considered an invalid LLC SAP value - I
        ** assume the SAP value in a DLPI bind is an LLC SAP for network
        ** types that use 802.2 LLC).
        */
        if ((dlbindreq(p->fd, 1537, p->errbuf) < 0 &&
             dlbindreq(p->fd, 2, p->errbuf) < 0) ||
             dlbindack(p->fd, (char *)buf, p->errbuf, NULL) < 0)
                goto bad;
#elif defined(DL_HP_RAWDLS)
        /*
        ** HP-UX 10.0x and 10.1x.
        */
        if (dl_dohpuxbind(p->fd, p->errbuf) < 0)
                goto bad;
        if (p->send_fd >= 0) {
                /*
                ** XXX - if this fails, just close send_fd and
                ** set it to -1, so that you can't send but can
                ** still receive?
                */
                if (dl_dohpuxbind(p->send_fd, p->errbuf) < 0)
                        goto bad;
        }
#else /* neither AIX nor HP-UX */
        /*
        ** Not Sinix, and neither AIX nor HP-UX - Solaris, and any other
        ** OS using DLPI.
        **/
        if (dlbindreq(p->fd, 0, p->errbuf) < 0 ||
            dlbindack(p->fd, (char *)buf, p->errbuf, NULL) < 0)
                goto bad;
#endif /* AIX vs. HP-UX vs. other */
#endif /* !HP-UX 9 and !HP-UX 10.20 or later and !SINIX */

#ifdef HAVE_SOLARIS
        if (isatm) {
                /*
                ** Have to turn on some special ATM promiscuous mode
                ** for SunATM.
                ** Do *NOT* turn regular promiscuous mode on; it doesn't
                ** help, and may break things.
                */
                if (strioctl(p->fd, A_PROMISCON_REQ, 0, NULL) < 0) {
                        snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                            "A_PROMISCON_REQ: %s", pcap_strerror(errno));
                        goto bad;
                }
        } else
#endif
        if (p->opt.promisc) {
                /*
                ** Enable promiscuous (not necessary on send FD)
                */
                if (dlpromisconreq(p->fd, DL_PROMISC_PHYS, p->errbuf) < 0 ||
                    dlokack(p->fd, "promisc_phys", (char *)buf, p->errbuf) < 0)
                        goto bad;

                /*
                ** Try to enable multicast (you would have thought
                ** promiscuous would be sufficient). (Skip if using
                ** HP-UX or SINIX) (Not necessary on send FD)
                */
#if !defined(__hpux) && !defined(sinix)
                if (dlpromisconreq(p->fd, DL_PROMISC_MULTI, p->errbuf) < 0 ||
                    dlokack(p->fd, "promisc_multi", (char *)buf, p->errbuf) < 0)
                        status = PCAP_WARNING;
#endif
        }
        /*
        ** Try to enable SAP promiscuity (when not in promiscuous mode
        ** when using HP-UX, when not doing SunATM on Solaris, and never
        ** under SINIX) (Not necessary on send FD)
        */
#ifndef sinix
        if (
#ifdef __hpux
            !p->opt.promisc &&
#endif
#ifdef HAVE_SOLARIS
            !isatm &&
#endif
            (dlpromisconreq(p->fd, DL_PROMISC_SAP, p->errbuf) < 0 ||
            dlokack(p->fd, "promisc_sap", (char *)buf, p->errbuf) < 0)) {
                /* Not fatal if promisc since the DL_PROMISC_PHYS worked */
                if (p->opt.promisc)
                        status = PCAP_WARNING;
                else
                        goto bad;
        }
#endif /* sinix */

        /*
        ** HP-UX 9, and HP-UX 10.20 or later, must bind after setting
        ** promiscuous options.
        */
#if defined(HAVE_HPUX9) || defined(HAVE_HPUX10_20_OR_LATER)
        if (dl_dohpuxbind(p->fd, p->errbuf) < 0)
                goto bad;
        /*
        ** We don't set promiscuous mode on the send FD, but we'll defer
        ** binding it anyway, just to keep the HP-UX 9/10.20 or later
        ** code together.
        */
        if (p->send_fd >= 0) {
                /*
                ** XXX - if this fails, just close send_fd and
                ** set it to -1, so that you can't send but can
                ** still receive?
                */
                if (dl_dohpuxbind(p->send_fd, p->errbuf) < 0)
                        goto bad;
        }
#endif

        /*
        ** Determine link type
        ** XXX - get SAP length and address length as well, for use
        ** when sending packets.
        */
        if (dlinforeq(p->fd, p->errbuf) < 0 ||
            dlinfoack(p->fd, (char *)buf, p->errbuf) < 0)
                goto bad;

        infop = &((union DL_primitives *)buf)->info_ack;
        if (pcap_process_mactype(p, infop->dl_mac_type) != 0)
                goto bad;

#ifdef  DLIOCRAW
        /*
        ** This is a non standard SunOS hack to get the full raw link-layer
        ** header.
        */
        if (strioctl(p->fd, DLIOCRAW, 0, NULL) < 0) {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "DLIOCRAW: %s",
                    pcap_strerror(errno));
                goto bad;
        }
#endif

        ss = p->snapshot;

        /*
        ** There is a bug in bufmod(7). When dealing with messages of
        ** less than snaplen size it strips data from the beginning not
        ** the end.
        **
        ** This bug is fixed in 5.3.2. Also, there is a patch available.
        ** Ask for bugid 1149065.
        */
#ifdef HAVE_SOLARIS
        release = get_release(&osmajor, &osminor, &osmicro);
        if (osmajor == 5 && (osminor <= 2 || (osminor == 3 && osmicro < 2)) &&
            getenv("BUFMOD_FIXED") == NULL) {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                "WARNING: bufmod is broken in SunOS %s; ignoring snaplen.",
                    release);
                ss = 0;
                status = PCAP_WARNING;
        }
#endif

#ifdef HAVE_SYS_BUFMOD_H
        /* Push and configure bufmod. */
        if (pcap_conf_bufmod(p, ss, p->md.timeout) != 0)
                goto bad;
#endif

        /*
        ** As the last operation flush the read side.
        */
        if (ioctl(p->fd, I_FLUSH, FLUSHR) != 0) {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "FLUSHR: %s",
                    pcap_strerror(errno));
                goto bad;
        }

        /* Allocate data buffer. */
        if (pcap_alloc_databuf(p) != 0)
                goto bad;

        /* Success - but perhaps with a warning */
        if (status < 0)
                status = 0;

        /*
         * "p->fd" is an FD for a STREAMS device, so "select()" and
         * "poll()" should work on it.
         */
        p->selectable_fd = p->fd;

        p->read_op = pcap_read_dlpi;
        p->inject_op = pcap_inject_dlpi;
        p->setfilter_op = install_bpf_program;  /* no kernel filtering */
        p->setdirection_op = NULL;      /* Not implemented.*/
        p->set_datalink_op = NULL;      /* can't change data link type */
        p->getnonblock_op = pcap_getnonblock_fd;
        p->setnonblock_op = pcap_setnonblock_fd;
        p->stats_op = pcap_stats_dlpi;
        p->close_op = pcap_close_dlpi;

        return (status);
bad:
        if (p->fd >= 0)
                close(p->fd);
        if (p->send_fd >= 0)
                close(p->send_fd);
        return (status);
}

/*
 * Split a device name into a device type name and a unit number;
 * return the a pointer to the beginning of the unit number, which
 * is the end of the device type name, and set "*unitp" to the unit
 * number.
 *
 * Returns NULL on error, and fills "ebuf" with an error message.
 */
static char *
split_dname(char *device, int *unitp, char *ebuf)
{
        char *cp;
        char *eos;
        long unit;

        /*
         * Look for a number at the end of the device name string.
         */
        cp = device + strlen(device) - 1;
        if (*cp < '0' || *cp > '9') {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s missing unit number",
                    device);
                return (NULL);
        }

        /* Digits at end of string are unit number */
        while (cp-1 >= device && *(cp-1) >= '0' && *(cp-1) <= '9')
                cp--;

        errno = 0;
        unit = strtol(cp, &eos, 10);
        if (*eos != '\0') {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s bad unit number", device);
                return (NULL);
        }
        if (errno == ERANGE || unit > INT_MAX) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s unit number too large",
                    device);
                return (NULL);
        }
        if (unit < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s unit number is negative",
                    device);
                return (NULL);
        }
        *unitp = (int)unit;
        return (cp);
}

static int
dl_doattach(int fd, int ppa, char *ebuf)
{
        bpf_u_int32 buf[MAXDLBUF];
        int err;

        if (dlattachreq(fd, ppa, ebuf) < 0)
                return (PCAP_ERROR);
        err = dlokack(fd, "attach", (char *)buf, ebuf);
        if (err < 0)
                return (err);
        return (0);
}

#ifdef DL_HP_RAWDLS
static int
dl_dohpuxbind(int fd, char *ebuf)
{
        int hpsap;
        int uerror;
        bpf_u_int32 buf[MAXDLBUF];

        /*
         * XXX - we start at 22 because we used to use only 22, but
         * that was just because that was the value used in some
         * sample code from HP.  With what value *should* we start?
         * Does it matter, given that we're enabling SAP promiscuity
         * on the input FD?
         */
        hpsap = 22;
        for (;;) {
                if (dlbindreq(fd, hpsap, ebuf) < 0)
                        return (-1);
                if (dlbindack(fd, (char *)buf, ebuf, &uerror) >= 0)
                        break;
                /*
                 * For any error other than a UNIX EBUSY, give up.
                 */
                if (uerror != EBUSY) {
                        /*
                         * dlbindack() has already filled in ebuf for
                         * this error.
                         */
                        return (-1);
                }

                /*
                 * For EBUSY, try the next SAP value; that means that
                 * somebody else is using that SAP.  Clear ebuf so
                 * that application doesn't report the "Device busy"
                 * error as a warning.
                 */
                *ebuf = '\0';
                hpsap++;
                if (hpsap > 100) {
                        strlcpy(ebuf,
                            "All SAPs from 22 through 100 are in use",
                            PCAP_ERRBUF_SIZE);
                        return (-1);
                }
        }
        return (0);
}
#endif

int
pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
{
#ifdef HAVE_SOLARIS
        int fd;
        union {
                u_int nunits;
                char pad[516];  /* XXX - must be at least 513; is 516
                                   in "atmgetunits" */
        } buf;
        char baname[2+1+1];
        u_int i;

        /*
         * We may have to do special magic to get ATM devices.
         */
        if ((fd = open("/dev/ba", O_RDWR)) < 0) {
                /*
                 * We couldn't open the "ba" device.
                 * For now, just give up; perhaps we should
                 * return an error if the problem is neither
                 * a "that device doesn't exist" error (ENOENT,
                 * ENXIO, etc.) or a "you're not allowed to do
                 * that" error (EPERM, EACCES).
                 */
                return (0);
        }

        if (strioctl(fd, A_GET_UNITS, sizeof(buf), (char *)&buf) < 0) {
                snprintf(errbuf, PCAP_ERRBUF_SIZE, "A_GET_UNITS: %s",
                    pcap_strerror(errno));
                return (-1);
        }
        for (i = 0; i < buf.nunits; i++) {
                snprintf(baname, sizeof baname, "ba%u", i);
                if (pcap_add_if(alldevsp, baname, 0, NULL, errbuf) < 0)
                        return (-1);
        }
#endif

        return (0);
}

static int
send_request(int fd, char *ptr, int len, char *what, char *ebuf)
{
        struct  strbuf  ctl;
        int     flags;

        ctl.maxlen = 0;
        ctl.len = len;
        ctl.buf = ptr;

        flags = 0;
        if (putmsg(fd, &ctl, (struct strbuf *) NULL, flags) < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "send_request: putmsg \"%s\": %s",
                    what, pcap_strerror(errno));
                return (-1);
        }
        return (0);
}

static int
recv_ack(int fd, int size, const char *what, char *bufp, char *ebuf, int *uerror)
{
        union   DL_primitives   *dlp;
        struct  strbuf  ctl;
        int     flags;

        /*
         * Clear out "*uerror", so it's only set for DL_ERROR_ACK/DL_SYSERR,
         * making that the only place where EBUSY is treated specially.
         */
        if (uerror != NULL)
                *uerror = 0;

        ctl.maxlen = MAXDLBUF;
        ctl.len = 0;
        ctl.buf = bufp;

        flags = 0;
        if (getmsg(fd, &ctl, (struct strbuf*)NULL, &flags) < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "recv_ack: %s getmsg: %s",
                    what, pcap_strerror(errno));
                return (PCAP_ERROR);
        }

        dlp = (union DL_primitives *) ctl.buf;
        switch (dlp->dl_primitive) {

        case DL_INFO_ACK:
        case DL_BIND_ACK:
        case DL_OK_ACK:
#ifdef DL_HP_PPA_ACK
        case DL_HP_PPA_ACK:
#endif
                /* These are OK */
                break;

        case DL_ERROR_ACK:
                switch (dlp->error_ack.dl_errno) {

                case DL_SYSERR:
                        if (uerror != NULL)
                                *uerror = dlp->error_ack.dl_unix_errno;
                        snprintf(ebuf, PCAP_ERRBUF_SIZE,
                            "recv_ack: %s: UNIX error - %s",
                            what, pcap_strerror(dlp->error_ack.dl_unix_errno));
                        if (dlp->error_ack.dl_unix_errno == EACCES)
                                return (PCAP_ERROR_PERM_DENIED);
                        break;

                default:
                        snprintf(ebuf, PCAP_ERRBUF_SIZE, "recv_ack: %s: %s",
                            what, dlstrerror(dlp->error_ack.dl_errno));
                        if (dlp->error_ack.dl_errno == DL_BADPPA)
                                return (PCAP_ERROR_NO_SUCH_DEVICE);
                        else if (dlp->error_ack.dl_errno == DL_ACCESS)
                                return (PCAP_ERROR_PERM_DENIED);
                        break;
                }
                return (PCAP_ERROR);

        default:
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "recv_ack: %s: Unexpected primitive ack %s",
                    what, dlprim(dlp->dl_primitive));
                return (PCAP_ERROR);
        }

        if (ctl.len < size) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "recv_ack: %s: Ack too small (%d < %d)",
                    what, ctl.len, size);
                return (PCAP_ERROR);
        }
        return (ctl.len);
}

static char *
dlstrerror(bpf_u_int32 dl_errno)
{
        static char errstring[6+2+8+1];

        switch (dl_errno) {

        case DL_ACCESS:
                return ("Improper permissions for request");

        case DL_BADADDR:
                return ("DLSAP addr in improper format or invalid");

        case DL_BADCORR:
                return ("Seq number not from outstand DL_CONN_IND");

        case DL_BADDATA:
                return ("User data exceeded provider limit");

        case DL_BADPPA:
#ifdef HAVE_DEV_DLPI
                /*
                 * With a single "/dev/dlpi" device used for all
                 * DLPI providers, PPAs have nothing to do with
                 * unit numbers.
                 */
                return ("Specified PPA was invalid");
#else
                /*
                 * We have separate devices for separate devices;
                 * the PPA is just the unit number.
                 */
                return ("Specified PPA (device unit) was invalid");
#endif

        case DL_BADPRIM:
                return ("Primitive received not known by provider");

        case DL_BADQOSPARAM:
                return ("QOS parameters contained invalid values");

        case DL_BADQOSTYPE:
                return ("QOS structure type is unknown/unsupported");

        case DL_BADSAP:
                return ("Bad LSAP selector");

        case DL_BADTOKEN:
                return ("Token used not an active stream");

        case DL_BOUND:
                return ("Attempted second bind with dl_max_conind");

        case DL_INITFAILED:
                return ("Physical link initialization failed");

        case DL_NOADDR:
                return ("Provider couldn't allocate alternate address");

        case DL_NOTINIT:
                return ("Physical link not initialized");

        case DL_OUTSTATE:
                return ("Primitive issued in improper state");

        case DL_SYSERR:
                return ("UNIX system error occurred");

        case DL_UNSUPPORTED:
                return ("Requested service not supplied by provider");

        case DL_UNDELIVERABLE:
                return ("Previous data unit could not be delivered");

        case DL_NOTSUPPORTED:
                return ("Primitive is known but not supported");

        case DL_TOOMANY:
                return ("Limit exceeded");

        case DL_NOTENAB:
                return ("Promiscuous mode not enabled");

        case DL_BUSY:
                return ("Other streams for PPA in post-attached");

        case DL_NOAUTO:
                return ("Automatic handling XID&TEST not supported");

        case DL_NOXIDAUTO:
                return ("Automatic handling of XID not supported");

        case DL_NOTESTAUTO:
                return ("Automatic handling of TEST not supported");

        case DL_XIDAUTO:
                return ("Automatic handling of XID response");

        case DL_TESTAUTO:
                return ("Automatic handling of TEST response");

        case DL_PENDING:
                return ("Pending outstanding connect indications");

        default:
                sprintf(errstring, "Error %02x", dl_errno);
                return (errstring);
        }
}

static char *
dlprim(bpf_u_int32 prim)
{
        static char primbuf[80];

        switch (prim) {

        case DL_INFO_REQ:
                return ("DL_INFO_REQ");

        case DL_INFO_ACK:
                return ("DL_INFO_ACK");

        case DL_ATTACH_REQ:
                return ("DL_ATTACH_REQ");

        case DL_DETACH_REQ:
                return ("DL_DETACH_REQ");

        case DL_BIND_REQ:
                return ("DL_BIND_REQ");

        case DL_BIND_ACK:
                return ("DL_BIND_ACK");

        case DL_UNBIND_REQ:
                return ("DL_UNBIND_REQ");

        case DL_OK_ACK:
                return ("DL_OK_ACK");

        case DL_ERROR_ACK:
                return ("DL_ERROR_ACK");

        case DL_SUBS_BIND_REQ:
                return ("DL_SUBS_BIND_REQ");

        case DL_SUBS_BIND_ACK:
                return ("DL_SUBS_BIND_ACK");

        case DL_UNITDATA_REQ:
                return ("DL_UNITDATA_REQ");

        case DL_UNITDATA_IND:
                return ("DL_UNITDATA_IND");

        case DL_UDERROR_IND:
                return ("DL_UDERROR_IND");

        case DL_UDQOS_REQ:
                return ("DL_UDQOS_REQ");

        case DL_CONNECT_REQ:
                return ("DL_CONNECT_REQ");

        case DL_CONNECT_IND:
                return ("DL_CONNECT_IND");

        case DL_CONNECT_RES:
                return ("DL_CONNECT_RES");

        case DL_CONNECT_CON:
                return ("DL_CONNECT_CON");

        case DL_TOKEN_REQ:
                return ("DL_TOKEN_REQ");

        case DL_TOKEN_ACK:
                return ("DL_TOKEN_ACK");

        case DL_DISCONNECT_REQ:
                return ("DL_DISCONNECT_REQ");

        case DL_DISCONNECT_IND:
                return ("DL_DISCONNECT_IND");

        case DL_RESET_REQ:
                return ("DL_RESET_REQ");

        case DL_RESET_IND:
                return ("DL_RESET_IND");

        case DL_RESET_RES:
                return ("DL_RESET_RES");

        case DL_RESET_CON:
                return ("DL_RESET_CON");

        default:
                (void) sprintf(primbuf, "unknown primitive 0x%x", prim);
                return (primbuf);
        }
}

static int
dlattachreq(int fd, bpf_u_int32 ppa, char *ebuf)
{
        dl_attach_req_t req;

        req.dl_primitive = DL_ATTACH_REQ;
        req.dl_ppa = ppa;

        return (send_request(fd, (char *)&req, sizeof(req), "attach", ebuf));
}

static int
dlbindreq(int fd, bpf_u_int32 sap, char *ebuf)
{

        dl_bind_req_t   req;

        memset((char *)&req, 0, sizeof(req));
        req.dl_primitive = DL_BIND_REQ;
        /* XXX - what if neither of these are defined? */
#if defined(DL_HP_RAWDLS)
        req.dl_max_conind = 1;                  /* XXX magic number */
        req.dl_service_mode = DL_HP_RAWDLS;
#elif defined(DL_CLDLS)
        req.dl_service_mode = DL_CLDLS;
#endif
        req.dl_sap = sap;

        return (send_request(fd, (char *)&req, sizeof(req), "bind", ebuf));
}

static int
dlbindack(int fd, char *bufp, char *ebuf, int *uerror)
{

        return (recv_ack(fd, DL_BIND_ACK_SIZE, "bind", bufp, ebuf, uerror));
}

static int
dlpromisconreq(int fd, bpf_u_int32 level, char *ebuf)
{
        dl_promiscon_req_t req;

        req.dl_primitive = DL_PROMISCON_REQ;
        req.dl_level = level;

        return (send_request(fd, (char *)&req, sizeof(req), "promiscon", ebuf));
}

static int
dlokack(int fd, const char *what, char *bufp, char *ebuf)
{

        return (recv_ack(fd, DL_OK_ACK_SIZE, what, bufp, ebuf, NULL));
}


static int
dlinforeq(int fd, char *ebuf)
{
        dl_info_req_t req;

        req.dl_primitive = DL_INFO_REQ;

        return (send_request(fd, (char *)&req, sizeof(req), "info", ebuf));
}

static int
dlinfoack(int fd, char *bufp, char *ebuf)
{

        return (recv_ack(fd, DL_INFO_ACK_SIZE, "info", bufp, ebuf, NULL));
}

#ifdef HAVE_DLPI_PASSIVE
/*
 * Enable DLPI passive mode. We do not care if this request fails, as this
 * indicates the underlying DLPI device does not support link aggregation.
 */
static void
dlpassive(int fd, char *ebuf)
{
        dl_passive_req_t req;
        bpf_u_int32 buf[MAXDLBUF];

        req.dl_primitive = DL_PASSIVE_REQ;

        if (send_request(fd, (char *)&req, sizeof(req), "dlpassive", ebuf) == 0)
            (void) dlokack(fd, "dlpassive", (char *)buf, ebuf);
}
#endif

#ifdef DL_HP_RAWDLS
/*
 * There's an ack *if* there's an error.
 */
static int
dlrawdatareq(int fd, const u_char *datap, int datalen)
{
        struct strbuf ctl, data;
        long buf[MAXDLBUF];     /* XXX - char? */
        union DL_primitives *dlp;
        int dlen;

        dlp = (union DL_primitives*) buf;

        dlp->dl_primitive = DL_HP_RAWDATA_REQ;
        dlen = DL_HP_RAWDATA_REQ_SIZE;

        /*
         * HP's documentation doesn't appear to show us supplying any
         * address pointed to by the control part of the message.
         * I think that's what raw mode means - you just send the raw
         * packet, you don't specify where to send it to, as that's
         * implied by the destination address.
         */
        ctl.maxlen = 0;
        ctl.len = dlen;
        ctl.buf = (void *)buf;

        data.maxlen = 0;
        data.len = datalen;
        data.buf = (void *)datap;

        return (putmsg(fd, &ctl, &data, 0));
}
#endif /* DL_HP_RAWDLS */

#if defined(HAVE_SOLARIS) && defined(HAVE_SYS_BUFMOD_H)
static char *
get_release(bpf_u_int32 *majorp, bpf_u_int32 *minorp, bpf_u_int32 *microp)
{
        char *cp;
        static char buf[32];

        *majorp = 0;
        *minorp = 0;
        *microp = 0;
        if (sysinfo(SI_RELEASE, buf, sizeof(buf)) < 0)
                return ("?");
        cp = buf;
        if (!isdigit((unsigned char)*cp))
                return (buf);
        *majorp = strtol(cp, &cp, 10);
        if (*cp++ != '.')
                return (buf);
        *minorp =  strtol(cp, &cp, 10);
        if (*cp++ != '.')
                return (buf);
        *microp =  strtol(cp, &cp, 10);
        return (buf);
}
#endif

#ifdef DL_HP_PPA_REQ
/*
 * Under HP-UX 10 and HP-UX 11, we can ask for the ppa
 */


/*
 * Determine ppa number that specifies ifname.
 *
 * If the "dl_hp_ppa_info_t" doesn't have a "dl_module_id_1" member,
 * the code that's used here is the old code for HP-UX 10.x.
 *
 * However, HP-UX 10.20, at least, appears to have such a member
 * in its "dl_hp_ppa_info_t" structure, so the new code is used.
 * The new code didn't work on an old 10.20 system on which Rick
 * Jones of HP tried it, but with later patches installed, it
 * worked - it appears that the older system had those members but
 * didn't put anything in them, so, if the search by name fails, we
 * do the old search.
 *
 * Rick suggests that making sure your system is "up on the latest
 * lancommon/DLPI/driver patches" is probably a good idea; it'd fix
 * that problem, as well as allowing libpcap to see packets sent
 * from the system on which the libpcap application is being run.
 * (On 10.20, in addition to getting the latest patches, you need
 * to turn the kernel "lanc_outbound_promisc_flag" flag on with ADB;
 * a posting to "comp.sys.hp.hpux" at
 *
 *      http://www.deja.com/[ST_rn=ps]/getdoc.xp?AN=558092266
 *
 * says that, to see the machine's outgoing traffic, you'd need to
 * apply the right patches to your system, and also set that variable
 * with:

echo 'lanc_outbound_promisc_flag/W1' | /usr/bin/adb -w /stand/vmunix /dev/kmem

 * which could be put in, for example, "/sbin/init.d/lan".
 *
 * Setting the variable is not necessary on HP-UX 11.x.
 */
static int
get_dlpi_ppa(register int fd, register const char *device, register int unit,
    register char *ebuf)
{
        register dl_hp_ppa_ack_t *ap;
        register dl_hp_ppa_info_t *ipstart, *ip;
        register int i;
        char dname[100];
        register u_long majdev;
        struct stat statbuf;
        dl_hp_ppa_req_t req;
        char buf[MAXDLBUF];
        char *ppa_data_buf;
        dl_hp_ppa_ack_t *dlp;
        struct strbuf ctl;
        int flags;
        int ppa;

        memset((char *)&req, 0, sizeof(req));
        req.dl_primitive = DL_HP_PPA_REQ;

        memset((char *)buf, 0, sizeof(buf));
        if (send_request(fd, (char *)&req, sizeof(req), "hpppa", ebuf) < 0)
                return (PCAP_ERROR);

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

        flags = 0;
        /*
         * DLPI may return a big chunk of data for a DL_HP_PPA_REQ. The normal
         * recv_ack will fail because it set the maxlen to MAXDLBUF (8192)
         * which is NOT big enough for a DL_HP_PPA_REQ.
         *
         * This causes libpcap applications to fail on a system with HP-APA
         * installed.
         *
         * To figure out how big the returned data is, we first call getmsg
         * to get the small head and peek at the head to get the actual data
         * length, and  then issue another getmsg to get the actual PPA data.
         */
        /* get the head first */
        if (getmsg(fd, &ctl, (struct strbuf *)NULL, &flags) < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "get_dlpi_ppa: hpppa getmsg: %s", pcap_strerror(errno));
                return (PCAP_ERROR);
        }

        dlp = (dl_hp_ppa_ack_t *)ctl.buf;
        if (dlp->dl_primitive != DL_HP_PPA_ACK) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "get_dlpi_ppa: hpppa unexpected primitive ack 0x%x",
                    (bpf_u_int32)dlp->dl_primitive);
                return (PCAP_ERROR);
        }

        if (ctl.len < DL_HP_PPA_ACK_SIZE) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "get_dlpi_ppa: hpppa ack too small (%d < %lu)",
                     ctl.len, (unsigned long)DL_HP_PPA_ACK_SIZE);
                return (PCAP_ERROR);
        }

        /* allocate buffer */
        if ((ppa_data_buf = (char *)malloc(dlp->dl_length)) == NULL) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "get_dlpi_ppa: hpppa malloc: %s", pcap_strerror(errno));
                return (PCAP_ERROR);
        }
        ctl.maxlen = dlp->dl_length;
        ctl.len = 0;
        ctl.buf = (char *)ppa_data_buf;
        /* get the data */
        if (getmsg(fd, &ctl, (struct strbuf *)NULL, &flags) < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "get_dlpi_ppa: hpppa getmsg: %s", pcap_strerror(errno));
                free(ppa_data_buf);
                return (PCAP_ERROR);
        }
        if (ctl.len < dlp->dl_length) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "get_dlpi_ppa: hpppa ack too small (%d < %d)",
                    ctl.len, dlp->dl_length);
                free(ppa_data_buf);
                return (PCAP_ERROR);
        }

        ap = (dl_hp_ppa_ack_t *)buf;
        ipstart = (dl_hp_ppa_info_t *)ppa_data_buf;
        ip = ipstart;

#ifdef HAVE_HP_PPA_INFO_T_DL_MODULE_ID_1
        /*
         * The "dl_hp_ppa_info_t" structure has a "dl_module_id_1"
         * member that should, in theory, contain the part of the
         * name for the device that comes before the unit number,
         * and should also have a "dl_module_id_2" member that may
         * contain an alternate name (e.g., I think Ethernet devices
         * have both "lan", for "lanN", and "snap", for "snapN", with
         * the former being for Ethernet packets and the latter being
         * for 802.3/802.2 packets).
         *
         * Search for the device that has the specified name and
         * instance number.
         */
        for (i = 0; i < ap->dl_count; i++) {
                if ((strcmp((const char *)ip->dl_module_id_1, device) == 0 ||
                     strcmp((const char *)ip->dl_module_id_2, device) == 0) &&
                    ip->dl_instance_num == unit)
                        break;

                ip = (dl_hp_ppa_info_t *)((u_char *)ipstart + ip->dl_next_offset);
        }
#else
        /*
         * We don't have that member, so the search is impossible; make it
         * look as if the search failed.
         */
        i = ap->dl_count;
#endif

        if (i == ap->dl_count) {
                /*
                 * Well, we didn't, or can't, find the device by name.
                 *
                 * HP-UX 10.20, whilst it has "dl_module_id_1" and
                 * "dl_module_id_2" fields in the "dl_hp_ppa_info_t",
                 * doesn't seem to fill them in unless the system is
                 * at a reasonably up-to-date patch level.
                 *
                 * Older HP-UX 10.x systems might not have those fields
                 * at all.
                 *
                 * Therefore, we'll search for the entry with the major
                 * device number of a device with the name "/dev/<dev><unit>",
                 * if such a device exists, as the old code did.
                 */
                snprintf(dname, sizeof(dname), "/dev/%s%d", device, unit);
                if (stat(dname, &statbuf) < 0) {
                        snprintf(ebuf, PCAP_ERRBUF_SIZE, "stat: %s: %s",
                            dname, pcap_strerror(errno));
                        return (PCAP_ERROR);
                }
                majdev = major(statbuf.st_rdev);

                ip = ipstart;

                for (i = 0; i < ap->dl_count; i++) {
                        if (ip->dl_mjr_num == majdev &&
                            ip->dl_instance_num == unit)
                                break;

                        ip = (dl_hp_ppa_info_t *)((u_char *)ipstart + ip->dl_next_offset);
                }
        }
        if (i == ap->dl_count) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "can't find /dev/dlpi PPA for %s%d", device, unit);
                return (PCAP_ERROR_NO_SUCH_DEVICE);
        }
        if (ip->dl_hdw_state == HDW_DEAD) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "%s%d: hardware state: DOWN\n", device, unit);
                free(ppa_data_buf);
                return (PCAP_ERROR);
        }
        ppa = ip->dl_ppa;
        free(ppa_data_buf);
        return (ppa);
}
#endif

#ifdef HAVE_HPUX9
/*
 * Under HP-UX 9, there is no good way to determine the ppa.
 * So punt and read it from /dev/kmem.
 */
static struct nlist nl[] = {
#define NL_IFNET 0
        { "ifnet" },
        { "" }
};

static char path_vmunix[] = "/hp-ux";

/* Determine ppa number that specifies ifname */
static int
get_dlpi_ppa(register int fd, register const char *ifname, register int unit,
    register char *ebuf)
{
        register const char *cp;
        register int kd;
        void *addr;
        struct ifnet ifnet;
        char if_name[sizeof(ifnet.if_name) + 1];

        cp = strrchr(ifname, '/');
        if (cp != NULL)
                ifname = cp + 1;
        if (nlist(path_vmunix, &nl) < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "nlist %s failed",
                    path_vmunix);
                return (-1);
        }
        if (nl[NL_IFNET].n_value == 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE,
                    "could't find %s kernel symbol",
                    nl[NL_IFNET].n_name);
                return (-1);
        }
        kd = open("/dev/kmem", O_RDONLY);
        if (kd < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "kmem open: %s",
                    pcap_strerror(errno));
                return (-1);
        }
        if (dlpi_kread(kd, nl[NL_IFNET].n_value,
            &addr, sizeof(addr), ebuf) < 0) {
                close(kd);
                return (-1);
        }
        for (; addr != NULL; addr = ifnet.if_next) {
                if (dlpi_kread(kd, (off_t)addr,
                    &ifnet, sizeof(ifnet), ebuf) < 0 ||
                    dlpi_kread(kd, (off_t)ifnet.if_name,
                    if_name, sizeof(ifnet.if_name), ebuf) < 0) {
                        (void)close(kd);
                        return (-1);
                }
                if_name[sizeof(ifnet.if_name)] = '\0';
                if (strcmp(if_name, ifname) == 0 && ifnet.if_unit == unit)
                        return (ifnet.if_index);
        }

        snprintf(ebuf, PCAP_ERRBUF_SIZE, "Can't find %s", ifname);
        return (-1);
}

static int
dlpi_kread(register int fd, register off_t addr,
    register void *buf, register u_int len, register char *ebuf)
{
        register int cc;

        if (lseek(fd, addr, SEEK_SET) < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "lseek: %s",
                    pcap_strerror(errno));
                return (-1);
        }
        cc = read(fd, buf, len);
        if (cc < 0) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "read: %s",
                    pcap_strerror(errno));
                return (-1);
        } else if (cc != len) {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "short read (%d != %d)", cc,
                    len);
                return (-1);
        }
        return (cc);
}
#endif

pcap_t *
pcap_create(const char *device, char *ebuf)
{
        pcap_t *p;

        p = pcap_create_common(device, ebuf);
        if (p == NULL)
                return (NULL);

        p->activate_op = pcap_activate_dlpi;
        return (p);
}