/*
* $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 */