#ifndef lint
static char rcsid[] =
"@(#) Header: inet.c,v 1.16 96/06/23 14:28:22 leres Exp (LBL)";
#endif
#include <sys/param.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#ifdef HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
#if __STDC__
struct mbuf;
struct rtentry;
#endif
#include <net/if.h>
#include <netinet/in.h>
#include <ctype.h>
#include <errno.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pcap.h>
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#include "pcap-int.h"
#ifdef IFF_LOOPBACK
#define ISLOOPBACK(p) ((p)->ifr_flags & IFF_LOOPBACK)
#else
#define ISLOOPBACK(p) (strcmp((p)->ifr_name, "lo0") == 0)
#endif
char *
pcap_lookupdev(errbuf)
register char *errbuf;
{
register int fd, minunit, n;
register char *cp, *ibuf = NULL;
register struct ifreq *ifrp, *ifend, *ifnext, *mp;
struct ifconf ifc;
struct ifreq ifr;
static char device[sizeof(ifrp->ifr_name) + 1];
int len = 8192;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
(void)sprintf(errbuf, "socket: %s", pcap_strerror(errno));
return (NULL);
}
while (1) {
ifc.ifc_len = len;
ifc.ifc_buf = ibuf = realloc(ibuf, len);
if (ibuf == NULL) {
close(fd);
return (NULL);
}
if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0) {
(void)close(fd);
free(ibuf);
return (NULL);
}
if (ifc.ifc_len + sizeof(ifr) < len)
break;
len *= 2;
}
ifrp = (struct ifreq *)ibuf;
ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
mp = NULL;
minunit = 666;
for (; ifrp < ifend; ifrp = ifnext) {
#if BSD - 0 >= 199006
n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
if (n < sizeof(*ifrp))
ifnext = ifrp + 1;
else
ifnext = (struct ifreq *)((char *)ifrp + n);
if (ifrp->ifr_addr.sa_family != AF_INET)
continue;
#else
ifnext = ifrp + 1;
#endif
strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
(void)sprintf(errbuf, "SIOCGIFFLAGS: %s",
pcap_strerror(errno));
(void)close(fd);
free(ibuf);
return (NULL);
}
if ((ifr.ifr_flags & IFF_UP) == 0 || ISLOOPBACK(&ifr))
continue;
for (cp = ifrp->ifr_name; !isdigit(*cp); ++cp)
continue;
n = atoi(cp);
if (n < minunit) {
minunit = n;
mp = ifrp;
}
}
free(ibuf);
(void)close(fd);
if (mp == NULL) {
(void)strcpy(errbuf, "no suitable device found");
return (NULL);
}
(void)strncpy(device, mp->ifr_name, sizeof(device) - 1);
device[sizeof(device) - 1] = '\0';
return (device);
}
int
pcap_lookupnet(device, netp, maskp, errbuf)
register char *device;
register bpf_u_int32 *netp, *maskp;
register char *errbuf;
{
register int fd;
register struct sockaddr_in *sin;
struct ifreq ifr;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
(void)sprintf(errbuf, "socket: %s", pcap_strerror(errno));
return (-1);
}
memset(&ifr, 0, sizeof(ifr));
#ifdef linux
ifr.ifr_addr.sa_family = AF_INET;
#endif
(void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
(void)sprintf(errbuf, "SIOCGIFADDR: %s: %s",
device, pcap_strerror(errno));
(void)close(fd);
return (-1);
}
sin = (struct sockaddr_in *)&ifr.ifr_addr;
*netp = sin->sin_addr.s_addr;
if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
(void)sprintf(errbuf, "SIOCGIFNETMASK: %s: %s",
device, pcap_strerror(errno));
(void)close(fd);
return (-1);
}
(void)close(fd);
*maskp = sin->sin_addr.s_addr;
if (*maskp == 0) {
if (IN_CLASSA(*netp))
*maskp = IN_CLASSA_NET;
else if (IN_CLASSB(*netp))
*maskp = IN_CLASSB_NET;
else if (IN_CLASSC(*netp))
*maskp = IN_CLASSC_NET;
else {
(void)sprintf(errbuf, "inet class for 0x%x unknown",
*netp);
return (-1);
}
}
*netp &= *maskp;
return (0);
}