/*

 *  $Id: libnet_if_addr.c,v 1.23 2004/04/13 17:32:28 mike Exp $

 *

 *  libnet

 *  libnet_if_addr.c - interface selection code

 *

 *  Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>

 *  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 */

#if (HAVE_CONFIG_H)

#include "../include/config.h"

#endif

#if (!(_WIN32) || (__CYGWIN__)) 

#include "../include/libnet.h"

#else

#include "../include/win32/libnet.h"

#endif

#ifdef HAVE_SYS_SOCKIO_H

#include <sys/sockio.h>

#endif

#include "../include/ifaddrlist.h"

#define MAX_IPADDR 512

#if !(__WIN32__)

/*

 * By testing if we can retrieve the FLAGS of an iface

 * we can know if it exists or not and if it is up.

 */

int 

libnet_check_iface(libnet_t *l)

{

    struct ifreq ifr;

    int fd, res;

    fd = socket(AF_INET, SOCK_DGRAM, 0);

    if (fd < 0)

    {

        snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s() socket: %s\n", __func__,

                strerror(errno));

        return (-1);

    }

    strncpy(ifr.ifr_name, l->device, sizeof(ifr.ifr_name) -1);

    ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';

    res = ioctl(fd, SIOCGIFFLAGS, (int8_t *)&ifr);

    if (res < 0)

    {

        snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s() ioctl: %s\n", __func__,

                strerror(errno));

    }

    else

    {

        if ((ifr.ifr_flags & IFF_UP) == 0)

        {

            snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): %s is down\n",

                    __func__, l->device);

	    res = -1;

        }

    }

    close(fd);

    return (res);

}

/*

 *  Return the interface list

 */

#ifdef HAVE_SOCKADDR_SA_LEN

#define NEXTIFR(i) \

((struct ifreq *)((u_char *)&i->ifr_addr + i->ifr_addr.sa_len))

#else

#define NEXTIFR(i) (i + 1)

#endif

#ifndef BUFSIZE

#define BUFSIZE 2048

#endif

#ifdef HAVE_LINUX_PROCFS

#define PROC_DEV_FILE "/proc/net/dev"

#endif

int

libnet_ifaddrlist(register struct libnet_ifaddr_list **ipaddrp, char *dev,

register char *errbuf)

{

    register struct libnet_ifaddr_list *al;

    struct ifreq *ifr, *lifr, *pifr, nifr;

    char device[sizeof(nifr.ifr_name)];

    static struct libnet_ifaddr_list ifaddrlist[MAX_IPADDR];

    char *p;

    struct ifconf ifc;

    struct ifreq ibuf[MAX_IPADDR];

    register int fd, nipaddr;

#ifdef HAVE_LINUX_PROCFS

    FILE *fp;

    char buf[2048];

#endif

    fd = socket(AF_INET, SOCK_DGRAM, 0);

    if (fd < 0)

    {

	snprintf(errbuf, LIBNET_ERRBUF_SIZE, "%s(): socket error: %s\n",

                __func__, strerror(errno));

	return (-1);

    }

#ifdef HAVE_LINUX_PROCFS

    if ((fp = fopen(PROC_DEV_FILE, "r")) == NULL)

    {

	snprintf(errbuf, LIBNET_ERRBUF_SIZE,

                "%s(): fopen(proc_dev_file) failed: %s\n",  __func__,

                strerror(errno));

	return (-1);

    }

#endif

    memset(&ifc, 0, sizeof(ifc));

    ifc.ifc_len = sizeof(ibuf);

    ifc.ifc_buf = (caddr_t)ibuf;

    if(ioctl(fd, SIOCGIFCONF, &ifc) < 0)

    {

	snprintf(errbuf, LIBNET_ERRBUF_SIZE,

                "%s(): ioctl(SIOCGIFCONF) error: %s\n", 

                __func__, strerror(errno));

#ifdef HAVE_LINUX_PROCFS

	fclose(fp);

#endif

	return(-1);

    }

    pifr = NULL;

    lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];

    al = ifaddrlist;

    nipaddr = 0;

#ifdef HAVE_LINUX_PROCFS

    while (fgets(buf, sizeof(buf), fp))

    {

	if ((p = strchr(buf, ':')) == NULL)

        {

            continue;

        }

        *p = '\0';

        for(p = buf; *p == ' '; p++) ;

        strncpy(nifr.ifr_name, p, sizeof(nifr.ifr_name) - 1);

        nifr.ifr_name[sizeof(nifr.ifr_name) - 1] = '\0';

#else /* !HAVE_LINUX_PROCFS */

    for (ifr = ifc.ifc_req; ifr < lifr; ifr = NEXTIFR(ifr))

    {

	/* XXX LINUX SOLARIS ifalias */

	if((p = strchr(ifr->ifr_name, ':')))

        {

            *p='\0';

        }

	if (pifr && strcmp(ifr->ifr_name, pifr->ifr_name) == 0)

        {

            continue;

        }

	strncpy(nifr.ifr_name, ifr->ifr_name, sizeof(nifr.ifr_name) - 1);

	nifr.ifr_name[sizeof(nifr.ifr_name) - 1] = '\0';

#endif

        /* save device name */

        strncpy(device, nifr.ifr_name, sizeof(device) - 1);

        device[sizeof(device) - 1] = '\0';

        if (ioctl(fd, SIOCGIFFLAGS, &nifr) < 0)

        {

            pifr = ifr;

            continue;

	}

        if ((nifr.ifr_flags & IFF_UP) == 0)

	{

            pifr = ifr;

            continue;	

	}

        if (dev == NULL && LIBNET_ISLOOPBACK(&nifr))

	{

            pifr = ifr;

            continue;

	}

        strncpy(nifr.ifr_name, device, sizeof(device) - 1);

        nifr.ifr_name[sizeof(nifr.ifr_name) - 1] = '\0';

        if (ioctl(fd, SIOCGIFADDR, (int8_t *)&nifr) < 0)

        {

            if (errno != EADDRNOTAVAIL)

            {

                snprintf(errbuf, LIBNET_ERRBUF_SIZE,

                        "%s(): SIOCGIFADDR: dev=%s: %s\n", __func__, device,

                        strerror(errno));

                close(fd);

#ifdef HAVE_LINUX_PROCFS

                fclose(fp);

#endif

                return (-1);

	    }

            else /* device has no IP address => set to 0 */

            {

                al->addr = 0;

            }

        }

        else

        {

            al->addr = ((struct sockaddr_in *)&nifr.ifr_addr)->sin_addr.s_addr;

        }

        free(al->device);

        al->device = NULL;

        if ((al->device = strdup(device)) == NULL)

        {

            snprintf(errbuf, LIBNET_ERRBUF_SIZE, 

                    "%s(): strdup not enough memory\n", __func__);

#ifdef HAVE_LINUX_PROCFS

            fclose(fp);

#endif

            return(-1);

        }

        ++al;

        ++nipaddr;

#ifndef HAVE_LINUX_PROCFS

        pifr = ifr;

#endif

    } /* while|for */

#ifdef HAVE_LINUX_PROCFS

    if (ferror(fp))

    {

        snprintf(errbuf, LIBNET_ERRBUF_SIZE,

                "%s(): ferror: %s\n", __func__, strerror(errno));

	fclose(fp);

	return (-1);

    }

    fclose(fp);

#endif

    *ipaddrp = ifaddrlist;

    return (nipaddr);

}

#else

/* From tcptraceroute, convert a numeric IP address to a string */

#define IPTOSBUFFERS    12

static int8_t *iptos(uint32_t in)

{

    static int8_t output[IPTOSBUFFERS][ 3 * 4 + 3 + 1];

    static int16_t which;

    uint8_t *p;

    p = (uint8_t *)∈

    which = (which + 1 == IPTOSBUFFERS ? 0 : which + 1);

    snprintf(output[which], IPTOSBUFFERS, "%d.%d.%d.%d", 

            p[0], p[1], p[2], p[3]);

    return output[which];

}

int

libnet_ifaddrlist(register struct libnet_ifaddr_list **ipaddrp, char *dev,

register char *errbuf)

{

    int nipaddr = 0;    int i = 0;

    static struct libnet_ifaddr_list ifaddrlist[MAX_IPADDR];

    pcap_if_t *alldevs;

    pcap_if_t *d;

    int8_t err[PCAP_ERRBUF_SIZE];

    /* Retrieve the interfaces list */

    if (pcap_findalldevs(&alldevs, err) == -1)

    {

        snprintf(errbuf, LIBNET_ERRBUF_SIZE, 

                "%s(): error in pcap_findalldevs: %s\n", __func__, err);

        return (-1);

    }

    /* Scan the list printing every entry */

	for (d = alldevs; d; d = d->next)

    {

		if((!d->addresses) || (d->addresses->addr->sa_family != AF_INET))

            continue;

        if(d->flags & PCAP_IF_LOOPBACK)

            continue;

		/* XXX - strdup */

        ifaddrlist[i].device = strdup(d->name);

        ifaddrlist[i].addr = (uint32_t)

                strdup(iptos(((struct sockaddr_in *)

                d->addresses->addr)->sin_addr.s_addr));

        ++i;

        ++nipaddr;

    }

    *ipaddrp = ifaddrlist;

    return (nipaddr);

}

#endif /* __WIN32__ */

int

libnet_select_device(libnet_t *l)

{

    int c, i;

    char err_buf[LIBNET_ERRBUF_SIZE];

    struct libnet_ifaddr_list *address_list, *al;

    uint32_t addr;

    if (l == NULL)

    { 

        return (-1);

    }

    if (l->device && !isdigit(l->device[0]))

    {

#if !(__WIN32__)

	if (libnet_check_iface(l) < 0)

	{

            /* err msg set in libnet_check_iface() */

	    return (-1);

	}

#endif

	return (1);

    }

    /*

     *  Number of interfaces.

     */

    c = libnet_ifaddrlist(&address_list, l->device, err_buf);

    if (c < 0)

    {

        /* err msg set in libnet_ifaddrlist() */

        return (-1);

    }

    else if (c == 0)

    {

        snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,

                "%s(): no network interface found\n", __func__);

        return (-1);

    }

    al = address_list;

    if (l->device)

    {

        /*

         *  Then we have an IP address in l->device => do lookup

         */

	addr = libnet_name2addr4(l, l->device, 0);

        for (i = c; i; --i, ++address_list)

        {

            if (((addr == -1) && !(strncmp(l->device, address_list->device,

                   strlen(l->device)))) || 

                    (address_list->addr == addr))

            {

                /* free the "user supplied device" - see libnet_init() */

                free(l->device);

                l->device =  strdup(address_list->device);

                goto good;

            }

        }

        if (i <= 0)

        {

            snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,

                    "%s(): can't find interface for IP %s\n", __func__,

                    l->device);

	    goto bad;

        }

    }

    else

    {

        l->device = strdup(address_list->device);

    }

good:

    for (i = 0; i < c; i++)

    {

        free(al[i].device);

        al[i].device = NULL;

    }

    return (1);

bad:

    for (i = 0; i < c; i++)

    {

        free(al[i].device);

        al[i].device = NULL;

    }

    return (-1);

}

/* EOF */