OpenBSD-4.6/lib/libpcap/inet.c
/* $OpenBSD: inet.c,v 1.19 2006/03/26 20:58:50 djm Exp $ */
/*
* Copyright (c) 1994, 1995, 1996, 1997, 1998
* 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 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Computer Systems
* Engineering Group at Lawrence Berkeley Laboratory.
* 4. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#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
#include <sys/time.h> /* concession to AIX */
struct mbuf;
struct rtentry;
#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>
#ifdef HAVE_IFADDRS_H
#include <ifaddrs.h>
#endif
#include "pcap-int.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
/*
* Free a list of interfaces.
*/
void
pcap_freealldevs(pcap_if_t *alldevs)
{
pcap_if_t *curdev, *nextdev;
pcap_addr_t *curaddr, *nextaddr;
for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
nextdev = curdev->next;
/*
* Free all addresses.
*/
for (curaddr = curdev->addresses; curaddr != NULL;
curaddr = nextaddr) {
nextaddr = curaddr->next;
if (curaddr->addr)
free(curaddr->addr);
if (curaddr->netmask)
free(curaddr->netmask);
if (curaddr->broadaddr)
free(curaddr->broadaddr);
if (curaddr->dstaddr)
free(curaddr->dstaddr);
free(curaddr);
}
/*
* Free the name string.
*/
free(curdev->name);
/*
* Free the description string, if any.
*/
if (curdev->description != NULL)
free(curdev->description);
/*
* Free the interface.
*/
free(curdev);
}
}
/*
* Return the name of a network interface attached to the system, or NULL
* if none can be found. The interface must be configured up; the
* lowest unit number is preferred; loopback is ignored.
*/
char *
pcap_lookupdev(errbuf)
register char *errbuf;
{
#ifdef HAVE_IFADDRS_H
struct ifaddrs *ifap, *ifa, *mp;
int n, minunit;
char *cp;
static char device[IF_NAMESIZE + 1];
if (getifaddrs(&ifap) != 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"getifaddrs: %s", pcap_strerror(errno));
return NULL;
}
mp = NULL;
minunit = 666;
for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
if ((ifa->ifa_flags & IFF_UP) == 0)
continue;
if (ISLOOPBACK(ifa->ifa_name, ifa->ifa_flags))
continue;
for (cp = ifa->ifa_name; !isdigit(*cp); ++cp)
continue;
n = atoi(cp);
if (n < minunit) {
minunit = n;
mp = ifa;
}
}
if (mp == NULL) {
(void)strlcpy(errbuf, "no suitable device found",
PCAP_ERRBUF_SIZE);
freeifaddrs(ifap);
return (NULL);
}
(void)strlcpy(device, mp->ifa_name, sizeof(device));
freeifaddrs(ifap);
return (device);
#else
register int fd, minunit, n;
register char *cp;
register struct ifreq *ifrp, *ifend, *ifnext, *mp;
struct ifconf ifc;
struct ifreq ibuf[16], ifr;
static char device[sizeof(ifrp->ifr_name) + 1];
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
pcap_strerror(errno));
return (NULL);
}
ifc.ifc_len = sizeof ibuf;
ifc.ifc_buf = (caddr_t)ibuf;
memset((char *)ibuf, 0, sizeof(ibuf));
if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
ifc.ifc_len < sizeof(struct ifreq)) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFCONF: %s",
pcap_strerror(errno));
(void)close(fd);
return (NULL);
}
ifrp = ibuf;
ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
mp = NULL;
minunit = 666;
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 *)((char *)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.)
*/
(void)strlcpy(ifr.ifr_name, ifrp->ifr_name,
sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
if (errno == ENXIO)
continue;
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFFLAGS: %.*s: %s",
(int)sizeof(ifr.ifr_name), ifr.ifr_name,
pcap_strerror(errno));
(void)close(fd);
return (NULL);
}
/* Must be up and not the loopback */
if ((ifr.ifr_flags & IFF_UP) == 0 ||
ISLOOPBACK(ifr.ifr_name, ifr.ifr_flags))
continue;
for (cp = ifrp->ifr_name; !isdigit(*cp); ++cp)
continue;
n = atoi(cp);
if (n < minunit) {
minunit = n;
mp = ifrp;
}
}
(void)close(fd);
if (mp == NULL) {
(void)strlcpy(errbuf, "no suitable device found",
PCAP_ERRBUF_SIZE);
return (NULL);
}
(void)strlcpy(device, mp->ifr_name, sizeof(device));
return (device);
#endif
}
int
pcap_lookupnet(const char *device, bpf_u_int32 *netp, bpf_u_int32 *maskp,
char *errbuf)
{
int fd;
struct sockaddr_in *sin;
struct ifreq ifr;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
pcap_strerror(errno));
return (-1);
}
memset(&ifr, 0, sizeof(ifr));
#ifdef linux
/* XXX Work around Linux kernel bug */
ifr.ifr_addr.sa_family = AF_INET;
#endif
(void)strlcpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
if (errno == EADDRNOTAVAIL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"%s: no IPv4 address assigned", device);
} else {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"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)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"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)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"inet class for 0x%x unknown", *netp);
return (-1);
}
}
*netp &= *maskp;
return (0);
}