libnet_if_addr.c

tcp数据流重放工具

/*
 *  $Id: libnet_if_addr.c,v 1.9 2003/10/18 17:33:10 mike Exp $
 *
 *  libnet
 *  libnet_if_addr.c - interface selection code
 *
 *  Copyright (c) 1998 - 2003 Mike D. Schiffman <[e-mail]>
 *  Originally pulled from traceroute sources.
 *  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 32

#if !(__WIN32__)
/*
 *  Return the interface list
 */
int
libnet_ifaddrlist(register struct libnet_ifaddr_list **ipaddrp,
            int8_t *dev, register int8_t *errbuf)
{
    register int fd, nipaddr;
#ifdef HAVE_SOCKADDR_SA_LEN
    register int n;
#endif
    register struct ifreq *ifrp, *ifend, *ifnext, *mp;
    register struct sockaddr_in *sin;
    register struct libnet_ifaddr_list *al;
    struct ifconf ifc;
    struct ifreq ibuf[MAX_IPADDR], ifr;
    int8_t device[sizeof(ifr.ifr_name)];
    static struct libnet_ifaddr_list ifaddrlist[MAX_IPADDR];

    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd < 0)
    {
        snprintf(errbuf, LIBNET_ERRBUF_SIZE, "socket: %s", strerror(errno));
        return (-1);
    }

	memset(&ifc, 0, sizeof(ifc));
	ifc.ifc_len = sizeof(ibuf);
    ifc.ifc_buf = (caddr_t)ibuf;

    if (ioctl(fd,
            SIOCGIFCONF,
            (int8_t *)&ifc) < 0 || ifc.ifc_len < sizeof(struct ifreq))
    {
        snprintf(errbuf, LIBNET_ERRBUF_SIZE, "SIOCGIFCONF: %s", strerror(errno));
        close(fd);
        return (-1);
    }
    ifrp = ibuf;
    ifend = (struct ifreq *)((int8_t *)ibuf + ifc.ifc_len);

    al = ifaddrlist;
    mp = NULL;
    nipaddr = 0;
    for (; ifrp < ifend; ifrp = ifnext)
    {
#ifdef HAVE_SOCKADDR_SA_LEN
        n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
        if (n < sizeof(*ifrp))
        {
            ifnext = ifrp + 1;
        }
        else
        {
            ifnext = (struct ifreq *)((int8_t *)ifrp + n);
        }
        if (ifrp->ifr_addr.sa_family != AF_INET) continue;
#else
        ifnext = ifrp + 1;
#endif
        /*
         * Need a template to preserve address info that is
         * used below to locate the next entry.  (Otherwise,
         * SIOCGIFFLAGS stomps over it because the requests
         * are returned in a union.)
         */
        strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name) -1);
		ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
        
		if (ioctl(fd, SIOCGIFFLAGS, (int8_t *)&ifr) < 0)
        {
            if (errno == ENXIO) continue;
            snprintf(errbuf, LIBNET_ERRBUF_SIZE,
                    "SIOCGIFFLAGS: %.*s: %s",
                    (int)sizeof(ifr.ifr_name),
                     ifr.ifr_name,
                     strerror(errno));
            close(fd);
            return (-1);
        }

        /* first make sure it's up */
        if ((ifr.ifr_flags & IFF_UP) == 0)
        {
            continue;
        }
        /* then we'll ignore loopback if device was NULL */
        if (dev == NULL &&  LIBNET_ISLOOPBACK(&ifr))
        {
            continue;
        }

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

        if (ioctl(fd, SIOCGIFADDR, (int8_t *)&ifr) < 0)
        {
            snprintf(errbuf, LIBNET_ERRBUF_SIZE,
				    "SIOCGIFADDR: %s: %s", device, strerror(errno));
            close(fd);
            return (-1);
        }
    
        sin = (struct sockaddr_in *)&ifr.ifr_addr;
        al->addr = sin->sin_addr.s_addr;
        /*
         *  Replaced savestr() with strdup().  -- MDS
         */
        al->device = strdup(device);
        ++al;
        ++nipaddr;
    }
    close(fd);

    *ipaddrp = ifaddrlist;
    return (nipaddr);
}
#else
/* From tcptraceroute, convert a numeric IP address to a string */
#define IPTOSBUFFERS    12
int8_t *iptos(u_int32_t in)
{
    static int8_t output[IPTOSBUFFERS][3*4+3+1];
    static int16_t which;
    u_int8_t *p;

    p = (u_int8_t *)&in;
    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,
            int8_t *dev, register int8_t *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,
                        "Error in pcap_findalldevs: %s", err);
		return(-1);
	}

	/* Scan the list printing every entry */
	for(d=alldevs;d;d=d->next)
	{
		if (d->addresses->addr->sa_family != AF_INET)
		{
			continue;
		}

		if (d->flags & PCAP_IF_LOOPBACK)
		{
			continue;
		}
      
		ifaddrlist[i].device = strdup(d->name);
		ifaddrlist[i].addr = 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;
    int8_t err_buf[LIBNET_ERRBUF_SIZE];
    struct libnet_ifaddr_list *address_list, *al;
    u_int32_t addr;

    if (l == NULL)
    { 
        return (-1);
    }

    /*
     *  Number of interfaces.
     */
    c = libnet_ifaddrlist(&address_list, l->device, err_buf);
    if (c < 0)
    {
        snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
                "ifaddrlist : %s\n", err_buf);
        return (-1);
    }
    else if (c == 0)
    {
        snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
                "No network interfaces found.\n");
        return (-1);
    }
	
    al = address_list;
    if (l->device)
    {
        /*
         *  If the device was specified as an IP address, find the first
         *  device that matches it.
         */
        if (isdigit(l->device[0]))
        {
            /* on error this will be -1 */
            addr = libnet_name2addr4(l, l->device, 0);
        }
        else
        {
            addr = -1;
        }

        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 %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);
    }
    return (1);

bad:
    for (i = 0; i < c; i++)
    {
        free(al[i].device);
    }
    return (-1);
}

/* EOF */